Control link for low-power and simplified transceiver

ABSTRACT

Methods, systems, and devices for wireless communications are described. The described techniques provide for detecting when a control link between a user equipment (UE) and a base station is lost and recovering the control link. In one example, a UE may detect that a control link with a base station is lost based on a timer or counter expiring or based on failing to receive signaling from the base station. In another example, a UE may be configured to transmit uplink transmissions to a base station to maintain a control link with the base station, and the base station may detect that a control link with the UE is lost if the base station fails to receive one or more uplink transmissions from the UE. If the control link is lost, the base station and the UE may communicate to re-establish the control link.

CROSS REFERENCE

The present application for patent is a continuation of U.S. patentapplication Ser. No. 17/234,512 by BAO et al., entitled “CONTROL LINKFOR LOW-POWER AND SIMPLIFIED TRANSCEIVER,” filed Apr. 19, 2021, assignedto the assignee hereof, and expressly incorporated by reference herein,which claims the benefit of U.S. Provisional Patent Application No.63/014,077 by BAO et al., entitled “CONTROL LINK FOR LOW-POWER ANDSIMPLIFIED TRANSCEIVER,” filed Apr. 22, 2020, assigned to the assigneehereof, and expressly incorporated by reference herein and U.S.Provisional Patent Application No. 63/014,075 by BAO et al., entitled“RANDOM-ACCESS PROCEDURE FOR LOW-POWER AND SIMPLIFIED TRANSCEIVER,”filed Apr. 22, 2020, assigned to the assignee hereof, and expresslyincorporated by reference herein.

INTRODUCTION

The following relates to wireless communications and more specificallyto managing a control link between a base station and a low-power andsimplified transceiver.

Wireless communications systems are widely deployed to provide varioustypes of communication content such as voice, video, packet data,messaging, broadcast, and so on. These systems may be capable ofsupporting communication with multiple users by sharing the availablesystem resources (e.g., time, frequency, and power). Examples of suchmultiple-access systems include fourth generation (4G) systems such asLong Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, orLTE-A Pro systems, and fifth generation (5G) systems which may bereferred to as New Radio (NR) systems. These systems may employtechnologies such as code division multiple access (CDMA), time divisionmultiple access (TDMA), frequency division multiple access (FDMA),orthogonal frequency division multiple access (OFDMA), or discreteFourier transform spread orthogonal frequency division multiplexing(DFT-S-OFDM).

A wireless multiple-access communications system may include one or morebase stations or one or more network access nodes, each simultaneouslysupporting communication for multiple communication devices, which maybe otherwise known as user equipment (UE). In some wirelesscommunications systems, a base station may transmit downlink data andcontrol information directly to a UE (e.g., using beamforming). In somecases, however, the path between the base station and the UE may beobstructed or blocked, which may affect the ability of the UE to receivea downlink transmission from the base station.

SUMMARY

A method for wireless communication at a first device is described. Themethod may include establishing a first link with the base station basedon a first random access procedure, the first link including a controllink associated with controlling a state of the first device, the firstdevice including a reflective surface for forwarding signals associatedwith a second link from the base station to a second device in awireless network, detecting that the first link with the base station islost based on a timer or counter expiring or based on failing to receivesignaling from the base station, and re-establishing the first link withthe base station based on detecting that the first link with the basestation is lost, the first link re-established based on a second randomaccess procedure.

An apparatus for wireless communication at a first device is described.The apparatus may include a processor and memory coupled to theprocessor. The processor and memory may be configured to establish afirst link with the base station based on a first random accessprocedure, the first link including a control link associated withcontrolling a state of the first device, the first device including areflective surface for forwarding signals associated with a second linkfrom the base station to a second device in a wireless network, detectthat the first link with the base station is lost based on a timer orcounter expiring or based on failing to receive signaling from the basestation, and re-establish the first link with the base station based ondetecting that the first link with the base station is lost, the firstlink re-established based on a second random access procedure.

Another apparatus for wireless communication at a first device isdescribed. The apparatus may include means for establishing a first linkwith the base station based on a first random access procedure, thefirst link including a control link associated with controlling a stateof the first device, the first device including a reflective surface forforwarding signals associated with a second link from the base stationto a second device in a wireless network, means for detecting that thefirst link with the base station is lost based on a timer or counterexpiring or based on failing to receive signaling from the base station,and means for re-establishing the first link with the base station basedon detecting that the first link with the base station is lost, thefirst link re-established based on a second random access procedure.

A non-transitory computer-readable medium storing code for wirelesscommunication at a first device is described. The code may includeinstructions executable by a processor to establish a first link withthe base station based on a first random access procedure, the firstlink including a control link associated with controlling a state of thefirst device, the first device including a reflective surface forforwarding signals associated with a second link from the base stationto a second device in a wireless network, detect that the first linkwith the base station is lost based on a timer or counter expiring orbased on failing to receive signaling from the base station, andre-establish the first link with the base station based on detectingthat the first link with the base station is lost, the first linkre-established based on a second random access procedure.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for failing to receive oneor more periodic indicators in a control channel, where detecting thatthe first link with the base station may be lost may be based on failingto receive the one or more periodic indicators in the control channel.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for incrementing thecounter after failing to receive each of the one or more periodicindicators in the control channel, where detecting that the first linkwith the base station may be lost may be based on the counter exceedinga threshold.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for decrementing thecounter after failing to receive each of the one or more periodicindicators in the control channel, where detecting that the first linkwith the base station may be lost may be based on the counter reachingzero.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for identifying that thefirst link with the base station may be valid for a duration of thetimer, where detecting that the first link with the base station may belost may be based on the timer expiring.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for failing to detectenergy from the base station for a duration of the timer, wheredetecting that the first link with the base station may be lost may bebased on failing to detect the energy from the base station for theduration of the timer.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for restarting the timerafter detecting the energy from the base station.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, performing the secondrandom-access procedure may include operations, features, means, orinstructions for performing a contention-free random-access procedureusing a cell radio network temporary identifier (C-RNTI) to re-establishthe first link with the base station.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for transmitting, to thebase station, a random-access preamble including an indication that thefirst device includes the reflective surface, the random-access preambleinitiating the first random-access procedure with the base station.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for identifying therandom-access preamble from one or more random-access preambles reservedfor indicating that the first device includes the reflective surface.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the first device includes auser equipment (UE), the second device includes a UE, and the seconddevice includes a base station.

A method for wireless communication at a base station is described. Themethod may include establishing a first link with a first device basedon a first random-access procedure, the first link including a controllink associated with controlling a state of the first device, the firstdevice including a reflective surface for forwarding signals associatedwith a second link from the base station to a second device in awireless network, transmitting signaling to the first device to maintainthe first link with the first device, and performing a secondrandom-access procedure to re-establish the first link with the firstdevice after the first link with the first device is lost.

An apparatus for wireless communication at a base station is described.The apparatus may include a processor and memory coupled to theprocessor. The processor and memory may be configured to establish afirst link with a first device based on a first random-access procedure,the first link including a control link associated with controlling astate of the first device, the first device including a reflectivesurface for forwarding signals associated with a second link from thebase station to a second device in a wireless network, transmitsignaling to the first device to maintain the first link with the firstdevice, and perform a second random-access procedure to re-establish thefirst link with the first device after the first link with the firstdevice is lost.

Another apparatus for wireless communication at a base station isdescribed. The apparatus may include means for establishing a first linkwith a first device based on a first random-access procedure, the firstlink including a control link associated with controlling a state of thefirst device, the first device including a reflective surface forforwarding signals associated with a second link from the base stationto a second device in a wireless network, means for transmittingsignaling to the first device to maintain the first link with the firstdevice, and means for performing a second random-access procedure tore-establish the first link with the first device after the first linkwith the first device is lost.

A non-transitory computer-readable medium storing code for wirelesscommunication at a base station is described. The code may includeinstructions executable by a processor to establish a first link with afirst device based on a first random-access procedure, the first linkincluding a control link associated with controlling a state of thefirst device, the first device including a reflective surface forforwarding signals associated with a second link from the base stationto a second device in a wireless network, transmit signaling to thefirst device to maintain the first link with the first device, andperform a second random-access procedure to re-establish the first linkwith the first device after the first link with the first device islost.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, transmitting signaling to thefirst device to maintain the first link with the first device mayinclude operations, features, means, or instructions for transmittingone or more periodic indicators in a control channel to the basestation, where the first link with the first device may be lost when thefirst device fails to receive a threshold number of the one or moreperiodic indicators.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for receiving, from thefirst device, a random-access preamble including an indication that thefirst device includes the reflective surface, the random-access preambleinitiating the first random-access procedure with the first device.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, performing the secondrandom-access procedure may include operations, features, means, orinstructions for performing a contention-free random-access procedureusing a cell radio network temporary identifier (C-RNTI) to re-establishthe first link with the first device.

A method for wireless communication at a first device is described. Themethod may include establishing a first link with a base station basedon a first random-access procedure, the first link including a controllink associated with controlling a state of the first device, the firstdevice including a reflective surface for forwarding signals associatedwith a second link from the base station to a second device in awireless network and transmitting an uplink transmission to the basestation to maintain the first link with the base station.

An apparatus for wireless communication at a first device is described.The apparatus may include a processor and memory coupled to theprocessor. The processor and memory may be configured to establish afirst link with a base station based on a first random-access procedure,the first link including a control link associated with controlling astate of the first device, the first device including a reflectivesurface for forwarding signals associated with a second link from thebase station to a second device in a wireless network and transmit anuplink transmission to the base station to maintain the first link withthe base station.

Another apparatus for wireless communication at a first device isdescribed. The apparatus may include means for establishing a first linkwith a base station based on a first random-access procedure, the firstlink including a control link associated with controlling a state of thefirst device, the first device including a reflective surface forforwarding signals associated with a second link from the base stationto a second device in a wireless network and means for transmitting anuplink transmission to the base station to maintain the first link withthe base station.

A non-transitory computer-readable medium storing code for wirelesscommunication at a first device is described. The code may includeinstructions executable by a processor to establish a first link with abase station based on a first random-access procedure, the first linkincluding a control link associated with controlling a state of thefirst device, the first device including a reflective surface forforwarding signals associated with a second link from the base stationto a second device in a wireless network and transmit an uplinktransmission to the base station to maintain the first link with thebase station.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the uplink transmissionincludes a scheduling request.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the uplink transmissionincludes a periodic uplink transmission.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for receiving a request forthe uplink transmission from the first device in response to a downlinktransmission and receiving the downlink transmission from the basestation, where the uplink transmission may be received in response tothe downlink transmission.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, transmitting the uplinktransmission to the base station may include operations, features,means, or instructions for transmitting a random-access preambleindicating a quantity of control commands received from the basestation.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for transmitting, to thebase station, a random-access preamble including an indication that thefirst device includes a reflective surface, the random-access preambleinitiating the first random-access procedure with the base station.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for identifying therandom-access preamble from one or more random-access preambles reservedfor indicating that the first device includes the reflective surface.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the first device includes aUE, the second device includes a UE, and the second device includes abase station.

A method for wireless communication at a base station is described. Themethod may include establishing a first link with a first device basedon a first random-access procedure, the first link including a controllink associated with controlling a state of the first device, the firstdevice including a reflective surface for forwarding signals associatedwith a second link from the base station to a second device in awireless network and receiving an uplink transmission from the firstdevice to maintain the first link with the base station.

An apparatus for wireless communication at a base station is described.The apparatus may include a processor and memory coupled to theprocessor. The processor and memory may be configured to establish afirst link with a first device based on a first random-access procedure,the first link including a control link associated with controlling astate of the first device, the first device including a reflectivesurface for forwarding signals associated with a second link from thebase station to a second device in a wireless network and receive anuplink transmission from the first device to maintain the first linkwith the base station.

Another apparatus for wireless communication at a base station isdescribed. The apparatus may include means for establishing a first linkwith a first device based on a first random-access procedure, the firstlink including a control link associated with controlling a state of thefirst device, the first device including a reflective surface forforwarding signals associated with a second link from the base stationto a second device in a wireless network and means for receiving anuplink transmission from the first device to maintain the first linkwith the base station.

A non-transitory computer-readable medium storing code for wirelesscommunication at a base station is described. The code may includeinstructions executable by a processor to establish a first link with afirst device based on a first random-access procedure, the first linkincluding a control link associated with controlling a state of thefirst device, the first device including a reflective surface forforwarding signals associated with a second link from the base stationto a second device in a wireless network and receive an uplinktransmission from the first device to maintain the first link with thebase station.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for failing to receive oneor more uplink transmissions from the first device, detecting that thefirst link with the first device may be lost based on failing to receivethe one or more uplink transmissions from the first device, and avoidingtransmitting downlink signals to the first device for forwarding to thedevice in the wireless network until the first device performs a secondrandom-access procedure to re-establish the first link with the basestation.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the uplink transmissionincludes a scheduling request.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the uplink transmissionincludes a periodic uplink transmission.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for transmitting a requestfor the uplink transmission from the first device in response to adownlink transmission and transmitting the downlink transmission to thefirst device, where the uplink transmission may be received in responseto the downlink transmission.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, receiving the uplinktransmission from the first device may include operations, features,means, or instructions for receiving a random-access preamble indicatinga first quantity of control commands received from the base station.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for determining that asecond quantity of control commands transmitted by the base stationexceeds the first quantity of control commands received by the firstdevice by a threshold amount, detecting that the first link with thefirst device may be lost based on the determining, and avoidingtransmitting downlink signals to the first device for forwarding to thedevice in the wireless network until the first device performs a secondrandom-access procedure to re-establish the first link with the basestation.

A method of wireless communication at a UE is described. The method mayinclude performing a first random-access procedure to establish acontrol link with a base station, the UE including a reflective surfacefor forwarding signals from the base station to a device in a wirelessnetwork, detecting that the control link with the base station is lostbased on a timer or counter expiring or based on failing to receivesignaling from the base station, and performing a second random-accessprocedure to re-establish the control link with the base station basedon detecting that the control link with the base station is lost.

An apparatus for wireless communication at a UE is described. Theapparatus may include a processor and memory coupled to the processor.The processor and memory may be configured to perform a firstrandom-access procedure to establish a control link with a base station,the UE including a reflective surface for forwarding signals from thebase station to a device in a wireless network, detect that the controllink with the base station is lost based on a timer or counter expiringor based on failing to receive signaling from the base station, andperform a second random-access procedure to re-establish the controllink with the base station based on detecting that the control link withthe base station is lost.

Another apparatus for wireless communication at a UE is described. Theapparatus may include means for performing a first random-accessprocedure to establish a control link with a base station, the UEincluding a reflective surface for forwarding signals from the basestation to a device in a wireless network, detecting that the controllink with the base station is lost based on a timer or counter expiringor based on failing to receive signaling from the base station, andperforming a second random-access procedure to re-establish the controllink with the base station based on detecting that the control link withthe base station is lost.

A non-transitory computer-readable medium storing code for wirelesscommunication at a UE is described. The code may include instructionsexecutable by a processor to perform a first random-access procedure toestablish a control link with a base station, the UE including areflective surface for forwarding signals from the base station to adevice in a wireless network, detect that the control link with the basestation is lost based on a timer or counter expiring or based on failingto receive signaling from the base station, and perform a secondrandom-access procedure to re-establish the control link with the basestation based on detecting that the control link with the base stationis lost.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for failing to receive oneor more periodic indicators in a control channel, where detecting thatthe control link with the base station may be lost may be based onfailing to receive the one or more periodic indicators in the controlchannel. Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for incrementing a counterafter failing to receive each of the one or more periodic indicators inthe control channel, where detecting that the control link with the basestation may be lost may be based on the counter exceeding a threshold.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for decrementing a counterafter failing to receive each of the one or more periodic indicators inthe control channel, where detecting that the control link with the basestation may be lost may be based on the counter reaching zero. Someexamples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for identifying that thecontrol link with the base station may be valid for a duration of thetimer, where detecting that the control link with the base station maybe lost may be based on the timer expiring.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for failing to detectenergy from the base station for a duration of the timer, wheredetecting that the control link with the base station may be lost may bebased on failing to detect the energy from the base station for theduration of the timer. Some examples of the method, apparatuses, andnon-transitory computer-readable medium described herein may furtherinclude operations, features, means, or instructions for restarting thetimer after detecting energy from the base station. In some examples ofthe method, apparatuses, and non-transitory computer-readable mediumdescribed herein, performing the second random-access procedure mayinclude operations, features, means, or instructions for performing acontention-free random-access procedure using a cell radio networktemporary identifier (C-RNTI) to re-establish the control link with thebase station.

A method of wireless communication at a base station is described. Themethod may include performing a first random-access procedure toestablish a control link with a UE, the UE including a reflectivesurface for forwarding signals from the base station to a device in awireless network, transmitting signaling to the UE to maintain thecontrol link with the UE, and performing a second random-accessprocedure to re-establish the control link with the UE after the controllink with the UE is lost.

An apparatus for wireless communication at a base station is described.The apparatus may include a processor and memory coupled to theprocessor. The processor and memory may be configured to perform a firstrandom-access procedure to establish a control link with a UE, the UEincluding a reflective surface for forwarding signals from the basestation to a device in a wireless network, transmit signaling to the UEto maintain the control link with the UE, and perform a secondrandom-access procedure to re-establish the control link with the UEafter the control link with the UE is lost.

Another apparatus for wireless communication at a base station isdescribed. The apparatus may include means for performing a firstrandom-access procedure to establish a control link with a UE, the UEincluding a reflective surface for forwarding signals from the basestation to a device in a wireless network, transmitting signaling to theUE to maintain the control link with the UE, and performing a secondrandom-access procedure to re-establish the control link with the UEafter the control link with the UE is lost.

A non-transitory computer-readable medium storing code for wirelesscommunication at a base station is described. The code may includeinstructions executable by a processor to perform a first random-accessprocedure to establish a control link with a UE, the UE including areflective surface for forwarding signals from the base station to adevice in a wireless network, transmit signaling to the UE to maintainthe control link with the UE, and perform a second random-accessprocedure to re-establish the control link with the UE after the controllink with the UE is lost.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, transmitting signaling to theUE to maintain the control link with the UE may include operations,features, means, or instructions for transmitting one or more periodicindicators in a control channel to the base station, where the controllink with the UE may be lost when the UE fails to receive a thresholdnumber of the one or more periodic indicators. In some examples of themethod, apparatuses, and non-transitory computer-readable mediumdescribed herein, performing the second random-access procedure mayinclude operations, features, means, or instructions for performing acontention-free random-access procedure using a cell radio networktemporary identifier (C-RNTI) to re-establish the control link with theUE.

A method of wireless communication at a UE is described. The method mayinclude performing a first random-access procedure to establish acontrol link with a base station, the UE including a reflective surfacefor forwarding signals from the base station to a device in a wirelessnetwork and transmitting an uplink transmission to the base station tomaintain the control link with the base station.

An apparatus for wireless communication at a UE is described. Theapparatus may include a processor and memory coupled to the processor.The processor and memory may be configured to perform a firstrandom-access procedure to establish a control link with a base station,the UE including a reflective surface for forwarding signals from thebase station to a device in a wireless network and transmit an uplinktransmission to the base station to maintain the control link with thebase station.

Another apparatus for wireless communication at a UE is described. Theapparatus may include means for performing a first random-accessprocedure to establish a control link with a base station, the UEincluding a reflective surface for forwarding signals from the basestation to a device in a wireless network and transmitting an uplinktransmission to the base station to maintain the control link with thebase station.

A non-transitory computer-readable medium storing code for wirelesscommunication at a UE is described. The code may include instructionsexecutable by a processor to perform a first random-access procedure toestablish a control link with a base station, the UE including areflective surface for forwarding signals from the base station to adevice in a wireless network and transmit an uplink transmission to thebase station to maintain the control link with the base station.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the uplink transmissionincludes a scheduling request. In some examples of the method,apparatuses, and non-transitory computer-readable medium describedherein, the uplink transmission includes a periodic uplink transmission.Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for receiving a request forthe uplink transmission from the UE in response to a downlinktransmission, and receiving the downlink transmission from the basestation, where the uplink transmission may be received in response tothe downlink transmission. In some examples of the method, apparatuses,and non-transitory computer-readable medium described herein,transmitting the uplink transmission to the base station may includeoperations, features, means, or instructions for transmitting arandom-access preamble indicating a quantity of control commandsreceived from the base station.

A method of wireless communication at a base station is described. Themethod may include performing a first random-access procedure toestablish a control link with a UE, the UE including a reflectivesurface for forwarding signals from the base station to a device in awireless network and receiving an uplink transmission from the UE usedto maintain the control link with the base station.

An apparatus for wireless communication at a base station is described.The apparatus may include a processor and memory coupled to theprocessor. The processor and memory may be configured to perform a firstrandom-access procedure to establish a control link with a UE, the UEincluding a reflective surface for forwarding signals from the basestation to a device in a wireless network and receive an uplinktransmission from the UE used to maintain the control link with the basestation.

Another apparatus for wireless communication at a base station isdescribed. The apparatus may include means for performing a firstrandom-access procedure to establish a control link with a UE, the UEincluding a reflective surface for forwarding signals from the basestation to a device in a wireless network and receiving an uplinktransmission from the UE used to maintain the control link with the basestation.

A non-transitory computer-readable medium storing code for wirelesscommunication at a base station is described. The code may includeinstructions executable by a processor to perform a first random-accessprocedure to establish a control link with a UE, the UE including areflective surface for forwarding signals from the base station to adevice in a wireless network and receive an uplink transmission from theUE used to maintain the control link with the base station.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for failing to receive oneor more uplink transmissions from the UE, detecting that the controllink with the UE may be lost based on failing to receive the one or moreuplink transmissions from the UE, and avoiding transmitting downlinksignals to the UE for forwarding to the device in the wireless networkuntil the UE performs a second random-access procedure to re-establishthe control link with the base station. In some examples of the method,apparatuses, and non-transitory computer-readable medium describedherein, the uplink transmission includes a scheduling request. In someexamples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the uplink transmissionincludes a periodic uplink transmission. Some examples of the method,apparatuses, and non-transitory computer-readable medium describedherein may further include operations, features, means, or instructionsfor transmitting a request for the uplink transmission from the UE inresponse to a downlink transmission, and transmitting the downlinktransmission to the UE, where the uplink transmission may be received inresponse to the downlink transmission.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, receiving the uplinktransmission from the UE may include operations, features, means, orinstructions for receiving a random-access preamble indicating a firstquantity of control commands received from the base station. Someexamples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for determining that asecond quantity of control commands transmitted by the base stationexceeds the first quantity of control commands received by the UE by athreshold amount, detecting that the control link with the UE may belost based on the determining, and avoiding transmitting downlinksignals to the UE for forwarding to the device in the wireless networkuntil the UE performs a second random-access procedure to re-establishthe control link with the base station.

A method of wireless communication at a UE is described. The method mayinclude initiating a random-access procedure to connect to a basestation, transmitting, to the base station, an indication that the UEincludes a reflective surface for forwarding signals from the basestation to a device in a wireless network, and receiving signals fromthe base station for forwarding to the device in the wireless networkbased on transmitting the indication.

An apparatus for wireless communication at a UE is described. Theapparatus may include a processor and memory coupled with the processor.The processor and memory may be configured to connect to a base station,transmit, to the base station, an indication that the UE includes areflective surface for forwarding signals from the base station to adevice in a wireless network, and receive signals from the base stationfor forwarding to the device in the wireless network based ontransmitting the indication.

Another apparatus for wireless communication at a UE is described. Theapparatus may include means for initiating a random-access procedure toconnect to a base station, transmitting, to the base station, anindication that the UE includes a reflective surface for forwardingsignals from the base station to a device in a wireless network, andreceiving signals from the base station for forwarding to the device inthe wireless network based on transmitting the indication.

A non-transitory computer-readable medium storing code for wirelesscommunication at a UE is described. The code may include instructionsexecutable by a processor to initiate a random-access procedure toconnect to a base station, transmit, to the base station, an indicationthat the UE includes a reflective surface for forwarding signals fromthe base station to a device in a wireless network, and receive signalsfrom the base station for forwarding to the device in the wirelessnetwork based on transmitting the indication.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, transmitting the indicationthat the UE may include operations, features, means, or instructions fortransmitting a random-access preamble indicating that the UE includesthe reflective surface. Some examples of the method, apparatuses, andnon-transitory computer-readable medium described herein may furtherinclude operations, features, means, or instructions for identifying therandom-access preamble from one or more random-access preambles reservedfor indicating that the UE includes the reflective surface. In someexamples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, transmitting the indicationthat the UE may include operations, features, means, or instructions fortransmitting a first random-access message in a two-step random-accessprocedure including the indication that the UE includes the reflectivesurface.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, transmitting the indicationthat the UE may include operations, features, means, or instructions fortransmitting a third random-access message in a four-step random-accessprocedure including the indication that the UE includes the reflectivesurface. In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, transmitting the indicationthat the UE may include operations, features, means, or instructions fortransmitting, after the random-access procedure, a radio resourcecontrol (RRC) message indicating that the UE includes the reflectivesurface. Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for receiving an indicationof one or more random-access preambles reserved for indicating that theUE includes the reflective surface, and transmitting, as part of asubsequent random-access procedure, a random-access preamble of the oneor more random-access preambles indicating that the UE includes thereflective surface.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for receiving, from thebase station, a command indicating a sweep pattern, sweep direction,center frequency, bandwidth, or a combination thereof for forwardingsignals from the base station to the device in the wireless network, andforwarding signals from the base station to the device in the wirelessnetwork based on receiving the command. Some examples of the method,apparatuses, and non-transitory computer-readable medium describedherein may further include operations, features, means, or instructionsfor receiving, from the base station, a command indicating positive ornegative feedback for signals forwarded from the base station to thedevice in the wireless network, tuning parameters for forwarding signalsfrom the base station to the device in the wireless network based on thecommand, and forwarding signals from the base station to the device inthe wireless network based on the tuning.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for transmitting anindication of a location of the device in the wireless network to thebase station. Some examples of the method, apparatuses, andnon-transitory computer-readable medium described herein may furtherinclude operations, features, means, or instructions for receiving oneor more signals from the base station, and reflecting the one or moresignals back to the base station at a same angle at which the one ormore signals may be received. In some examples of the method,apparatuses, and non-transitory computer-readable medium describedherein, the UE includes a low-power UE and the reflective surfaceincludes an intelligent reflective surface (IRS).

A method of wireless communication at a base station is described. Themethod may include receiving, from a UE, an indication that the UEincludes a reflective surface for forwarding signals from the basestation to a device in a wireless network and transmitting signals tothe UE for forwarding to the device in the wireless network based onreceiving the indication.

An apparatus for wireless communication at a base station is described.The apparatus may include a processor and memory coupled to theprocessor. The processor and memory may be configured to receive, from aUE, an indication that the UE includes a reflective surface forforwarding signals from the base station to a device in a wirelessnetwork and transmit signals to the UE for forwarding to the device inthe wireless network based on receiving the indication.

Another apparatus for wireless communication at a base station isdescribed. The apparatus may include means for receiving, from a UE, anindication that the UE includes a reflective surface for forwardingsignals from the base station to a device in a wireless network andtransmitting signals to the UE for forwarding to the device in thewireless network based on receiving the indication.

A non-transitory computer-readable medium storing code for wirelesscommunication at a base station is described. The code may includeinstructions executable by a processor to receive, from a UE, anindication that the UE includes a reflective surface for forwardingsignals from the base station to a device in a wireless network andtransmit signals to the UE for forwarding to the device in the wirelessnetwork based on receiving the indication.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, receiving the indication thatthe UE may include operations, features, means, or instructions forreceiving a random-access preamble indicating that the UE includes thereflective surface. In some examples of the method, apparatuses, andnon-transitory computer-readable medium described herein, receiving theindication that the UE may include operations, features, means, orinstructions for receiving a first random-access message in a two-steprandom-access procedure including the indication that the UE includesthe reflective surface. In some examples of the method, apparatuses, andnon-transitory computer-readable medium described herein, receiving theindication that the UE may include operations, features, means, orinstructions for receiving a third random-access message in a four-steprandom-access procedure including the indication that the UE includesthe reflective surface.

In some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, receiving the indication thatthe UE may include operations, features, means, or instructions forreceiving, after a random-access procedure, a RRC message indicatingthat the UE includes the reflective surface. Some examples of themethod, apparatuses, and non-transitory computer-readable mediumdescribed herein may further include operations, features, means, orinstructions for transmitting, to the UE, an indication of one or morerandom-access preambles reserved for indicating that the UE includes thereflective surface, and receiving, from the UE as part of a subsequentrandom-access procedure, a random-access preamble of the one or morerandom-access preambles indicating that the UE includes the reflectivesurface. Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for transmitting, to theUE, a command indicating a sweep pattern, sweep direction, centerfrequency, bandwidth, or a combination thereof for forwarding signalsfrom the base station to the device in the wireless network.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for receiving, from thedevice in the wireless network, feedback on signals forwarded by the UEfrom the base station to the device in the wireless network, wheretransmitting the command may be based on the received feedback. Someexamples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for receiving, from thedevice in the wireless network, feedback on signals forwarded by the UEfrom the base station to the device in the wireless network, andtransmitting, to the UE, a command indicating positive or negativefeedback for signals forwarded from the base station to the device inthe wireless network based on receiving the feedback.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for transmitting, to the UEon a set of beams, a set of signals for forwarding to the device in thewireless network, receiving, from the device in the wireless network,feedback on the set of signals forwarded by the UE from the base stationto the device in the wireless network, identifying a beam of the set ofbeams associated with a highest quality based on the received feedback,and selecting the identified beam for transmitting signals to the UE forforwarding to the device in the wireless network. Some examples of themethod, apparatuses, and non-transitory computer-readable mediumdescribed herein may further include operations, features, means, orinstructions for receiving an indication of a location of the UE, andselecting a beam for transmitting signals to the UE for forwarding tothe device in the wireless network based on the location of the UE.

Some examples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for transmitting a set ofsignals to the UE on a set of beams, receiving a reflection of the setof signals from the UE at a same angle at which the set of signals maybe transmitted to the UE on the set of beams, identifying a beam of theset of beams associated with a highest quality based on receiving thereflection, and selecting the identified beam for transmitting signalsto the UE for forwarding to the device in the wireless network. Someexamples of the method, apparatuses, and non-transitorycomputer-readable medium described herein may further includeoperations, features, means, or instructions for selecting a beamidentified in the random-access procedure for transmitting signals tothe UE for forwarding to the device in the wireless network. In someexamples of the method, apparatuses, and non-transitorycomputer-readable medium described herein, the UE includes a low-powerUE and the reflective surface includes an IRS.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a wireless communications system thatsupports a control link for a low-power and simplified transceiver inaccordance with one or more aspects of the present disclosure.

FIG. 2 illustrates an example of a process flow illustrating a two-steprandom-access procedure in accordance with one or more aspects of thepresent disclosure.

FIG. 3 illustrates an example of a process flow illustrating a four-steprandom-access procedure in accordance with one or more aspects of thepresent disclosure.

FIG. 4 illustrates an example of an intelligent reflective surface (IRS)in accordance with one or more aspects of the present disclosure.

FIG. 5 illustrates an example of the flow of communications between abase station, an IRS, and a UE in accordance with one or more aspects ofthe present disclosure.

FIG. 6 illustrates an example of a wireless communications system thatsupports a control link for a low-power and simplified transceiver inaccordance with one or more aspects of the present disclosure.

FIG. 7 illustrates an example of a process flow that supports a controllink for a low-power and simplified transceiver in accordance with oneor more aspects of the present disclosure.

FIG. 8 illustrates an example of a process flow that supports a controllink for a low-power and simplified transceiver in accordance with oneor more aspects of the present disclosure.

FIG. 9 illustrates an example of the flow of communications between abase station, an IRS, and a UE in accordance with one or more aspects ofthe present disclosure.

FIG. 10 illustrates an example of a wireless communications system thatsupports a control link for a low-power and simplified transceiver inaccordance with one or more aspects of the present disclosure.

FIG. 11 illustrates an example of a process flow that supports a controllink for a low-power and simplified transceiver in accordance with oneor more aspects of the present disclosure.

FIGS. 12 and 13 show block diagrams of devices that support a controllink for a low-power and simplified transceiver in accordance with oneor more aspects of the present disclosure.

FIG. 14 shows a block diagram of a communications manager that supportsa control link for a low-power and simplified transceiver in accordancewith one or more aspects of the present disclosure.

FIG. 15 shows a diagram of a system including a device that supports acontrol link for a low-power and simplified transceiver in accordancewith one or more aspects of the present disclosure.

FIGS. 16 and 17 show block diagrams of devices that support a controllink for a low-power and simplified transceiver in accordance with oneor more aspects of the present disclosure.

FIG. 18 shows a block diagram of a communications manager that supportsa control link for a low-power and simplified transceiver in accordancewith one or more aspects of the present disclosure.

FIG. 19 shows a diagram of a system including a device that supports acontrol link for a low-power and simplified transceiver in accordancewith one or more aspects of the present disclosure.

FIGS. 20 and 21 show block diagrams of devices that support a controllink for a low-power and simplified transceiver in accordance with oneor more aspects of the present disclosure.

FIG. 22 shows a block diagram of a communications manager that supportsa control link for a low-power and simplified transceiver in accordancewith one or more aspects of the present disclosure.

FIG. 23 shows a diagram of a system including a device that supports acontrol link for a low-power and simplified transceiver in accordancewith one or more aspects of the present disclosure.

FIGS. 24 and 25 show block diagrams of devices that support a controllink for a low-power and simplified transceiver in accordance with oneor more aspects of the present disclosure.

FIG. 26 shows a block diagram of a communications manager that supportsa control link for a low-power and simplified transceiver in accordancewith one or more aspects of the present disclosure.

FIG. 27 shows a diagram of a system including a device that supports acontrol link for a low-power and simplified transceiver in accordancewith one or more aspects of the present disclosure.

FIGS. 28 through 41 show flowcharts illustrating methods that support acontrol link for a low-power and simplified transceiver in accordancewith one or more aspects of the present disclosure.

DETAILED DESCRIPTION

Some wireless communications systems may support communications betweena base station and another device (e.g., a UE or another base station)via an intelligent reflective surface (IRS). In particular, the basestation may transmit downlink signals to the IRS for forwarding to theother device. The IRS may redirect the downlink signals to the otherdevice such that the other device may reliably receive the downlinksignals from the base station (e.g., even when there is an obstructionin the path between the base station and the other device). In suchsystems, it may be appropriate for the IRS to connect to the basestation to forward signals from the base station to other devices. Insome examples, forwarding signals may include reflecting signalsreceived from the base station to other devices and may be described asredirecting, relaying, or routing the signals. For example, it may beappropriate for the IRS to establish a control link with the basestation to receive control information from the base station andestablish a data link with the base station to receive downlink signalsfrom the base station for forwarding to other devices. In some cases,however, it may be challenging for the IRS to maintain the control linkwith the base station (e.g., if the IRS is set up for minimalcommunication with the base station).

As described herein, a UE and a base station in a wirelesscommunications system may detect when a control link between the UE andthe base station is lost and recover the control link. Specifically, theUE and the base station may maintain the control link with minimalsignaling. In one example, the UE may detect that a control link with abase station is lost based on a timer or counter expiring or based onfailing to receive signaling from the base station. For example, thebase station may be configured to transmit signaling to the UE tomaintain the control link with the UE, and the UE may detect that thecontrol link is lost when the UE fails to receive the signaling. Inanother example, a UE may transmit uplink signals to a base station tomaintain a control link with the base station, and, if the base stationfails to receive one or more of the uplink signals, the base station maydetermine that the control link with the UE is lost. In this example,the base station may wait until the control link is re-established totransmit downlink signals to the UE for forwarding to another device.

Aspects of the disclosure introduced above are described below in thecontext of a wireless communications system. Examples of processes andsignaling exchanges that support a control link for a low-power andsimplified transceiver are then described. Aspects of the disclosure arefurther illustrated by and described with reference to apparatusdiagrams, system diagrams, and flowcharts that relate to a control linkfor a low-power and simplified transceiver.

FIG. 1 illustrates an example of a wireless communications system 100that supports a control link for a low-power and simplified transceiverin accordance with one or more aspects of the present disclosure. Thewireless communications system 100 may include one or more base stations105, one or more UEs 115, and a core network 130. In some examples, thewireless communications system 100 may be an LTE network, an LTE-Anetwork, an LTE-A Pro network, or an NR network. In some examples, thewireless communications system 100 may support enhanced broadbandcommunications, ultra-reliable (e.g., mission critical) communications,low latency communications, communications with low-cost andlow-complexity devices, or any combination thereof.

The base stations 105 may be dispersed throughout a geographic area toform the wireless communications system 100 and may be devices indifferent forms or having different capabilities. The base stations 105and the UEs 115 may wirelessly communicate via one or more communicationlinks 125. Each base station 105 may provide a coverage area 110 overwhich the UEs 115 and the base station 105 may establish one or morecommunication links 125. The coverage area 110 may be an example of ageographic area over which a base station 105 and a UE 115 may supportthe communication of signals according to one or more radio accesstechnologies.

The UEs 115 may be dispersed throughout a coverage area 110 of thewireless communications system 100, and each UE 115 may be stationary,or mobile, or both at different times. The UEs 115 may be devices indifferent forms or having different capabilities. Some example UEs 115are illustrated in FIG. 1 . The UEs 115 described herein may be able tocommunicate with various types of devices, such as other UEs 115, thebase stations 105, or network equipment (e.g., core network nodes, relaydevices, integrated access and backhaul (IAB) nodes, or other networkequipment), as shown in FIG. 1 .

The base stations 105 may communicate with the core network 130, or withone another, or both. For example, the base stations 105 may interfacewith the core network 130 through one or more backhaul links 120 (e.g.,via an S1, N2, N3, or other interface). The base stations 105 maycommunicate with one another over the backhaul links 120 (e.g., via anX2, Xn, or other interface) either directly (e.g., directly between basestations 105), or indirectly (e.g., via core network 130), or both. Insome examples, the backhaul links 120 may be or include one or morewireless links. A UE 115 may communicate with the core network 130through a communication link 155.

One or more of the base stations 105 described herein may include or maybe referred to by a person having ordinary skill in the art as a basetransceiver station, a radio base station, an access point, a radiotransceiver, a NodeB, an eNodeB (eNB), a next-generation NodeB or agiga-NodeB (either of which may be referred to as a gNB), a Home NodeB,a Home eNodeB, or other suitable terminology.

A UE 115 may include or may be referred to as a mobile device, awireless device, a remote device, a handheld device, or a subscriberdevice, or some other suitable terminology, where the “device” may alsobe referred to as a unit, a station, a terminal, or a client, amongother examples. A UE 115 may also include or may be referred to as apersonal electronic device such as a cellular phone, a personal digitalassistant (PDA), a tablet computer, a laptop computer, or a personalcomputer. In some examples, a UE 115 may include or be referred to as awireless local loop (WLL) station, an Internet of Things (IoT) device,an Internet of Everything (IoE) device, or a machine type communications(MTC) device, among other examples, which may be implemented in variousobjects such as appliances, or vehicles, meters, among other examples.

The UEs 115 described herein may be able to communicate with varioustypes of devices, such as other UEs 115 that may sometimes act as relaysas well as the base stations 105 and the network equipment includingmacro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations,among other examples, as shown in FIG. 1 .

The UEs 115 and the base stations 105 may wirelessly communicate withone another via one or more communication links 125 over one or morecarriers. The term “carrier” may refer to a set of radio frequencyspectrum resources having a defined physical layer structure forsupporting the communication links 125. For example, a carrier used fora communication link 125 may include a portion of a radio frequencyspectrum band (e.g., a bandwidth part (BWP)) that is operated accordingto one or more physical layer channels for a given radio accesstechnology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layerchannel may carry acquisition signaling (e.g., synchronization signals,system information), control signaling that coordinates operation forthe carrier, user data, or other signaling. The wireless communicationssystem 100 may support communication with a UE 115 using carrieraggregation or multi-carrier operation. A UE 115 may be configured withmultiple downlink component carriers and one or more uplink componentcarriers according to a carrier aggregation configuration. Carrieraggregation may be used with both frequency division duplexing (FDD) andtime division duplexing (TDD) component carriers.

In some examples (e.g., in a carrier aggregation configuration), acarrier may also have acquisition signaling or control signaling thatcoordinates operations for other carriers. A carrier may be associatedwith a frequency channel (e.g., an evolved universal mobiletelecommunication system terrestrial radio access (E-UTRA) absoluteradio frequency channel number (EARFCN)) and may be positioned accordingto a channel raster for discovery by the UEs 115. A carrier may beoperated in a standalone mode where initial acquisition and connectionmay be conducted by the UEs 115 via the carrier, or the carrier may beoperated in a non-standalone mode where a connection is anchored using adifferent carrier (e.g., of the same or a different radio accesstechnology).

The communication links 125 shown in the wireless communications system100 may include uplink transmissions from a UE 115 to a base station 105(e.g., in a physical uplink control channel (PUCCH) or a physical uplinkshared channel (PUSCH)), or downlink transmissions from a base station105 to a UE 115 (e.g., in a physical downlink control channel (PDCCH) ora physical downlink shared channel (PDSCH)). Carriers may carry downlinkor uplink communications (e.g., in an FDD mode) or may be configured tocarry downlink and uplink communications (e.g., in a TDD mode).

A carrier may be associated with a particular bandwidth of the radiofrequency spectrum, and in some examples the carrier bandwidth may bereferred to as a “system bandwidth” of the carrier or the wirelesscommunications system 100. For example, the carrier bandwidth may be oneof a number of determined bandwidths for carriers of a particular radioaccess technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 megahertz(MHz)). Devices of the wireless communications system 100 (e.g., thebase stations 105, the UEs 115, or both) may have hardwareconfigurations that support communications over a particular carrierbandwidth or may be configurable to support communications over one of aset of carrier bandwidths. In some examples, the wireless communicationssystem 100 may include base stations 105 or UEs 115 that supportsimultaneous communications via carriers associated with multiplecarrier bandwidths. In some examples, each served UE 115 may beconfigured for operating over portions (e.g., a sub-band, a BWP) or allof a carrier bandwidth.

Signal waveforms transmitted over a carrier may be made up of multiplesubcarriers (e.g., using multi-carrier modulation (MCM) techniques suchas orthogonal frequency division multiplexing (OFDM) or discrete Fouriertransform spread OFDM (DFT-S-OFDM)). In a system employing MCMtechniques, a resource element may consist of one symbol period (e.g., aduration of one modulation symbol) and one subcarrier, where the symbolperiod and subcarrier spacing are inversely related. The number of bitscarried by each resource element may depend on the modulation scheme(e.g., the order of the modulation scheme, the coding rate of themodulation scheme, or both). Thus, the more resource elements that a UE115 receives and the higher the order of the modulation scheme, thehigher the data rate may be for the UE 115. A wireless communicationsresource may refer to a combination of a radio frequency spectrumresource, a time resource, and a spatial resource (e.g., spatial layersor beams), and the use of multiple spatial layers may further increasethe data rate or data integrity for communications with a UE 115.

The time intervals for the base stations 105 or the UEs 115 may beexpressed in multiples of a basic time unit which may, for example,refer to a sampling period of T_(s)=1/(Δf_(max)·N_(f)) seconds, whereΔf_(max) may represent the maximum supported subcarrier spacing, andN_(f) may represent the maximum supported discrete Fourier transform(DFT) size. Time intervals of a communications resource may be organizedaccording to radio frames each having a specified duration (e.g., 10milliseconds (ms)). Each radio frame may be identified by a system framenumber (SFN) (e.g., ranging from 0 to 1023).

Each frame may include multiple consecutively numbered subframes orslots, and each subframe or slot may have the same duration. In someexamples, a frame may be divided (e.g., in the time domain) intosubframes, and each subframe may be further divided into a number ofslots. Alternatively, each frame may include a variable number of slots,and the number of slots may depend on subcarrier spacing. Each slot mayinclude a number of symbol periods (e.g., depending on the length of thecyclic prefix prepended to each symbol period). In some wirelesscommunications systems 100, a slot may further be divided into multiplemini-slots containing one or more symbols. Excluding the cyclic prefix,each symbol period may contain one or more (e.g., N_(f)) samplingperiods. The duration of a symbol period may depend on the subcarrierspacing or frequency band of operation.

A subframe, a slot, a mini-slot, or a symbol may be the smallestscheduling unit (e.g., in the time domain) of the wirelesscommunications system 100 and may be referred to as a transmission timeinterval (TTI). In some examples, the TTI duration (e.g., the number ofsymbol periods in a TTI) may be variable. Additionally, oralternatively, the smallest scheduling unit of the wirelesscommunications system 100 may be dynamically selected (e.g., in burstsof shortened TTIs (sTTIs)).

Physical channels may be multiplexed on a carrier according to varioustechniques. A physical control channel and a physical data channel maybe multiplexed on a downlink carrier, for example, using one or more oftime division multiplexing (TDM) techniques, frequency divisionmultiplexing (FDM) techniques, or hybrid TDM-FDM techniques. A controlregion (e.g., a control resource set (CORESET)) for a physical controlchannel may be defined by a number of symbol periods and may extendacross the system bandwidth or a subset of the system bandwidth of thecarrier. One or more control regions (e.g., CORESETs) may be configuredfor a set of the UEs 115. For example, one or more of the UEs 115 maymonitor or search control regions for control information according toone or more search space sets, and each search space set may include oneor multiple control channel candidates in one or more aggregation levelsarranged in a cascaded manner. An aggregation level for a controlchannel candidate may refer to a number of control channel resources(e.g., control channel elements (CCEs)) associated with encodedinformation for a control information format having a given payloadsize. Search space sets may include common search space sets configuredfor sending control information to multiple UEs 115 and UE-specificsearch space sets for sending control information to a specific UE 115.

In some examples, a base station 105 may be movable and thereforeprovide communication coverage for a moving geographic coverage area110. In some examples, different geographic coverage areas 110associated with different technologies may overlap, but the differentgeographic coverage areas 110 may be supported by the same base station105. In other examples, the overlapping geographic coverage areas 110associated with different technologies may be supported by differentbase stations 105. The wireless communications system 100 may include,for example, a heterogeneous network in which different types of thebase stations 105 provide coverage for various geographic coverage areas110 using the same or different radio access technologies.

Some UEs 115, such as MTC or IoT devices, may be low cost or lowcomplexity devices and may provide for automated communication betweenmachines (e.g., via Machine-to-Machine (M2M) communication). M2Mcommunication or MTC may refer to data communication technologies thatallow devices to communicate with one another or a base station 105without human intervention. In some examples, M2M communication or MTCmay include communications from devices that integrate sensors or metersto measure or capture information and relay such information to acentral server or application program that makes use of the informationor presents the information to humans interacting with the applicationprogram. Some UEs 115 may be designed to collect information or enableautomated behavior of machines or other devices. Examples ofapplications for MTC devices include smart metering, inventorymonitoring, water level monitoring, equipment monitoring, healthcaremonitoring, wildlife monitoring, weather and geological eventmonitoring, fleet management and tracking, remote security sensing,physical access control, and transaction-based business charging.

Some UEs 115 may be configured to employ operating modes that reducepower consumption, such as half-duplex communications (e.g., a mode thatsupports one-way communication via transmission or reception, but nottransmission and reception simultaneously). In some examples,half-duplex communications may be performed at a reduced peak rate.Other power conservation techniques for the UEs 115 include entering apower saving deep sleep mode when not engaging in active communications,operating over a limited bandwidth (e.g., according to narrowbandcommunications), or a combination of these techniques. For example, someUEs 115 may be configured for operation using a narrowband protocol typethat is associated with a defined portion or range (e.g., set ofsubcarriers or resource blocks (RBs)) within a carrier, within aguard-band of a carrier, or outside of a carrier.

The wireless communications system 100 may be configured to supportultra-reliable communications or low-latency communications, or variouscombinations thereof. For example, the wireless communications system100 may be configured to support ultra-reliable low-latencycommunications (URLLC) or mission critical communications. The UEs 115may be designed to support ultra-reliable, low-latency, or criticalfunctions (e.g., mission critical functions). Ultra-reliablecommunications may include private communication or group communicationand may be supported by one or more mission critical services such asmission critical push-to-talk (MCPTT), mission critical video (MCVideo),or mission critical data (MCData). Support for mission criticalfunctions may include prioritization of services, and mission criticalservices may be used for public safety or general commercialapplications. The terms ultra-reliable, low-latency, mission critical,and ultra-reliable low-latency may be used interchangeably herein.

In some examples, a UE 115 may also be able to communicate directly withother UEs 115 over a device-to-device (D2D) communication link 135(e.g., using a peer-to-peer (P2P) or D2D protocol). One or more UEs 115utilizing D2D communications may be within the geographic coverage area110 of a base station 105. Other UEs 115 in such a group may be outsidethe geographic coverage area 110 of a base station 105 or be otherwiseunable to receive transmissions from a base station 105. In someexamples, groups of the UEs 115 communicating via D2D communications mayutilize a one-to-many (1:M) system in which each UE 115 transmits toevery other UE 115 in the group. In some examples, a base station 105facilitates the scheduling of resources for D2D communications. In othercases, D2D communications are carried out between the UEs 115 withoutthe involvement of a base station 105.

The core network 130 may provide user authentication, accessauthorization, tracking, Internet Protocol (IP) connectivity, and otheraccess, routing, or mobility functions. The core network 130 may be anevolved packet core (EPC) or 5G core (5GC), which may include at leastone control plane entity that manages access and mobility (e.g., amobility management entity (MME), an access and mobility managementfunction (AMF)) and at least one user plane entity that routes packetsor interconnects to external networks (e.g., a serving gateway (S-GW), aPacket Data Network (PDN) gateway (P-GW), or a user plane function(UPF)). The control plane entity may manage non-access stratum (NAS)functions such as mobility, authentication, and bearer management forthe UEs 115 served by the base stations 105 associated with the corenetwork 130. User IP packets may be transferred through the user planeentity, which may provide IP address allocation as well as otherfunctions. The user plane entity may be connected to the networkoperators IP services 150. The operators IP services 150 may includeaccess to the Internet, Intranet(s), an IP Multimedia Subsystem (IMS),or a Packet-Switched Streaming Service.

Some of the network devices, such as a base station 105, may includesubcomponents such as an access network entity 140, which may be anexample of an access node controller (ANC). Each access network entity140 may communicate with the UEs 115 through one or more other accessnetwork transmission entities 145, which may be referred to as radioheads, smart radio heads, or transmission/reception points (TRPs). Eachaccess network transmission entity 145 may include one or more antennapanels. In some configurations, various functions of each access networkentity 140 or base station 105 may be distributed across various networkdevices (e.g., radio heads and ANCs) or consolidated into a singlenetwork device (e.g., a base station 105).

The electromagnetic spectrum is often subdivided, based onfrequency/wavelength, into various classes, bands, channels, etc. In 5GNR two initial operating bands have been identified as frequency rangedesignations FR1 (410 MHz-7.125 GHz) and FR2 (24.25 GHz-52.6 GHz). Itshould be understood that although a portion of FR1 is greater than 6GHz, FR1 is often referred to (interchangeably) as a “Sub-6 GHz” band invarious documents and articles. A similar nomenclature issue sometimesoccurs with regard to FR2, which is often referred to (interchangeably)as a “millimeter wave” band in documents and articles, despite beingdifferent from the extremely high frequency (EHF) band (30 GHz-300 GHz)which is identified by the International Telecommunications Union (ITU)as a “millimeter wave” band.

The frequencies between FR1 and FR2 are often referred to as mid-bandfrequencies. Recent 5G NR studies have identified an operating band forthese mid-band frequencies as frequency range designation FR3 (7.125GHz-24.25 GHz). Frequency bands falling within FR3 may inherit FR1characteristics or FR2 characteristics, and thus may effectively extendfeatures of FR1 or FR2 into mid-band frequencies. In addition, higherfrequency bands are currently being explored to extend 5G NR operationbeyond 52.6 GHz. For example, three higher operating bands have beenidentified as frequency range designations FR4a or FR4-1 (52.6 GHz-71GHz), FR4 (52.6 GHz-114.25 GHz), and FR5 (114.25 GHz-300 GHz). Each ofthese higher frequency bands falls within the EHF band.

With the above aspects in mind, unless specifically stated otherwise, itshould be understood that the term “sub-6 GHz” or the like if usedherein may broadly represent frequencies that may be less than 6 GHz,may be within FR1, or may include mid-band frequencies. Further, unlessspecifically stated otherwise, it should be understood that the term“millimeter wave” or the like if used herein may broadly representfrequencies that may include mid-band frequencies, may be within FR2,FR4, FR4-a or FR4-1, or FR5, or may be within the EHF band.

The wireless communications system 100 may operate using one or morefrequency bands, for example in the range of 300 megahertz (MHz) to 300gigahertz (GHz). The region from 300 MHz to 3 GHz is known as theultra-high frequency (UHF) region or decimeter band because thewavelengths range from approximately one decimeter to one meter inlength. The UHF waves may be blocked or redirected by buildings andenvironmental features, but the waves may penetrate structuressufficiently for a macro cell to provide service to the UEs 115 locatedindoors. The transmission of UHF waves may be associated with smallerantennas and shorter ranges (e.g., less than 100 kilometers) compared totransmission using the smaller frequencies and longer waves of the highfrequency (HF) or very high frequency (VHF) portion of the spectrumbelow 300 MHz.

The wireless communications system 100 may utilize both licensed andunlicensed radio frequency spectrum bands. For example, the wirelesscommunications system 100 may employ License Assisted Access (LAA),LTE-Unlicensed (LTE-U) radio access technology, or NR technology in anunlicensed band such as the 5 GHz industrial, scientific, and medical(ISM) band. When operating in unlicensed radio frequency spectrum bands,devices such as the base stations 105 and the UEs 115 may employ carriersensing for collision detection and avoidance. In some examples,operations in unlicensed bands may be based on a carrier aggregationconfiguration in conjunction with component carriers operating in alicensed band (e.g., LAA). Operations in unlicensed spectrum may includedownlink transmissions, uplink transmissions, P2P transmissions, or D2Dtransmissions, among other examples.

A base station 105 or a UE 115 may be equipped with multiple antennas,which may be used to employ techniques such as transmit diversity,receive diversity, multiple-input multiple-output (MIMO) communications,or beamforming. The antennas of a base station 105 or a UE 115 may belocated within one or more antenna arrays or antenna panels, which maysupport MIMO operations or transmit or receive beamforming. For example,one or more base station antennas or antenna arrays may be co-located atan antenna assembly, such as an antenna tower. In some examples,antennas or antenna arrays associated with a base station 105 may belocated in diverse geographic locations. A base station 105 may have anantenna array with a number of rows and columns of antenna ports thatthe base station 105 may use to support beamforming of communicationswith a UE 115. Likewise, a UE 115 may have one or more antenna arraysthat may support various MIMO or beamforming operations. Additionally,or alternatively, an antenna panel may support radio frequencybeamforming for a signal transmitted via an antenna port.

Beamforming, which may also be referred to as spatial filtering,directional transmission, or directional reception, is a signalprocessing technique that may be used at a transmitting device or areceiving device (e.g., a base station 105, a UE 115) to shape or steeran antenna beam (e.g., a transmit beam, a receive beam) along a spatialpath between the transmitting device and the receiving device.Beamforming may be achieved by combining the signals communicated viaantenna elements of an antenna array such that some signals propagatingat particular orientations with respect to an antenna array experienceconstructive interference while others experience destructiveinterference. The adjustment of signals communicated via the antennaelements may include a transmitting device or a receiving deviceapplying amplitude offsets, phase offsets, or both to signals carriedvia the antenna elements associated with the device. The adjustmentsassociated with each of the antenna elements may be defined by abeamforming weight set associated with a particular orientation (e.g.,with respect to the antenna array of the transmitting device orreceiving device, or with respect to some other orientation).

A base station 105 or a UE 115 may use beam sweeping techniques as partof beam forming operations. For example, a base station 105 may usemultiple antennas or antenna arrays (e.g., antenna panels) to conductbeamforming operations for directional communications with a UE 115.Some signals (e.g., synchronization signals, reference signals, beamselection signals, or other control signals) may be transmitted by abase station 105 multiple times in different directions. For example,the base station 105 may transmit a signal according to differentbeamforming weight sets associated with different directions oftransmission. Transmissions in different beam directions may be used toidentify (e.g., by a transmitting device, such as a base station 105, orby a receiving device, such as a UE 115) a beam direction for latertransmission or reception by the base station 105.

Some signals, such as data signals associated with a particularreceiving device, may be transmitted by a base station 105 in a singlebeam direction (e.g., a direction associated with the receiving device,such as a UE 115). In some examples, the beam direction associated withtransmissions along a single beam direction may be determined based on asignal that was transmitted in one or more beam directions. For example,a UE 115 may receive one or more of the signals transmitted by the basestation 105 in different directions and may report to the base station105 an indication of the signal that the UE 115 received with a highestsignal quality or an otherwise acceptable signal quality.

In some examples, transmissions by a device (e.g., by a base station 105or a UE 115) may be performed using multiple beam directions, and thedevice may use a combination of digital precoding or radio frequencybeamforming to generate a combined beam for transmission (e.g., from abase station 105 to a UE 115). The UE 115 may report feedback thatindicates precoding weights for one or more beam directions, and thefeedback may correspond to a configured number of beams across a systembandwidth or one or more sub-bands. The base station 105 may transmit areference signal (e.g., a cell-specific reference signal (CRS), achannel state information reference signal (CSI-RS)), which may beprecoded or unprecoded. The UE 115 may provide feedback for beamselection, which may be a precoding matrix indicator (PMI) orcodebook-based feedback (e.g., a multi-panel type codebook, a linearcombination type codebook, a port selection type codebook). Althoughthese techniques are described with reference to signals transmitted inone or more directions by a base station 105, a UE 115 may employsimilar techniques for transmitting signals multiple times in differentdirections (e.g., for identifying a beam direction for subsequenttransmission or reception by the UE 115) or for transmitting a signal ina single direction (e.g., for transmitting data to a receiving device).

A receiving device (e.g., a UE 115) may try multiple receiveconfigurations (e.g., directional listening) when receiving varioussignals from the base station 105, such as synchronization signals,reference signals, beam selection signals, or other control signals. Forexample, a receiving device may try multiple receive directions byreceiving via different antenna subarrays, by processing receivedsignals according to different antenna subarrays, by receiving accordingto different receive beamforming weight sets (e.g., differentdirectional listening weight sets) applied to signals received atmultiple antenna elements of an antenna array, or by processing receivedsignals according to different receive beamforming weight sets appliedto signals received at multiple antenna elements of an antenna array,any of which may be referred to as “listening” according to differentreceive configurations or receive directions. In some examples, areceiving device may use a single receive configuration to receive alonga single beam direction (e.g., when receiving a data signal). The singlereceive configuration may be aligned in a beam direction determinedbased on listening according to different receive configurationdirections (e.g., a beam direction determined to have a highest signalstrength, highest signal-to-noise ratio (SNR), or otherwise acceptablesignal quality based on listening according to multiple beamdirections).

The wireless communications system 100 may be a packet-based networkthat operates according to a layered protocol stack. In the user plane,communications at the bearer or Packet Data Convergence Protocol (PDCP)layer may be IP-based. A Radio Link Control (RLC) layer may performpacket segmentation and reassembly to communicate over logical channels.A Medium Access Control (MAC) layer may perform priority handling andmultiplexing of logical channels into transport channels. The MAC layermay also use error detection techniques, error correction techniques, orboth to support retransmissions at the MAC layer to improve linkefficiency. In the control plane, the Radio Resource Control (RRC)protocol layer may provide establishment, configuration, and maintenanceof an RRC connection between a UE 115 and a base station 105 or a corenetwork 130 supporting radio bearers for user plane data. At thephysical layer, transport channels may be mapped to physical channels.

The UEs 115 and the base stations 105 may support retransmissions ofdata to increase the likelihood that data is received successfully.Hybrid automatic repeat request (HARQ) feedback is one technique forincreasing the likelihood that data is received correctly over acommunication link 125. HARQ feedback may include an acknowledgment(ACK) indicating that a receiving device successfully received atransmission from a transmitting device or a negative ACK (NACK)indicating that a receiving device failed to receive a transmission froma transmitting device. HARQ may include a combination of error detection(e.g., using a cyclic redundancy check (CRC)), forward error correction(FEC), and retransmission (e.g., automatic repeat request (ARQ)). HARQmay improve throughput at the MAC layer in poor radio conditions (e.g.,low signal-to-noise conditions). In some examples, a device may supportsame-slot HARQ feedback, where the device may provide HARQ feedback in aspecific slot for data received in a previous symbol in the slot. Inother cases, the device may provide HARQ feedback in a subsequent slot,or according to some other time interval.

In wireless communications system 100, a UE 115 may use a random-accessprocedure to establish or re-establish a connection with a base station105 or identify suitable parameters and configurations for communicatingwith the base station 105. Wireless communications system 100 maysupport four-step random-access procedures and two-step random-accessprocedures. A four-step random-access procedure may include four messageexchanges between a UE 115 and a base station 105, and a two-steprandom-access procedure may include two message exchanges between a UE115 and a base station 105. In both procedures, it may be appropriatefor a UE 115 to transmit data or control information to a base station105. In a four-step random-access procedure, the UE 115 may transmit thedata or control information in a third random-access message (e.g., arandom-access Message 3 (Msg3)) to the base station 105. In a two-steprandom-access procedure, the UE 115 may transmit the data or controlinformation in a first random-access message (e.g., MSG1 or MsgA) to thebase station 105. In some examples, of the wireless communications 100,a UE 115 (e.g., an IRS UE 115) may include a reflective surface forrelaying signals from base station 105 to another device (e.g., anotherbase station 105 or UE 115). For example, a base station 105 maytransmit signaling to a UE 115 which is out of a coverage area 110 ofthe base station 105, or is outside of a line-of-sight path from basestation 105, via an IRS UE 115. In such examples, the IRS UE 115 mayperform a random-access procedure to establish a control link with abase station 105 such that the base station 105 may configured a stateof the IRS UE 115.

A base station 105 may include a communications manager 101.Communications manager 101 may perform a first random-access procedureto establish a control link with a UE 115, the UE 115 including areflective surface for forwarding signals from the base station 105 to adevice in wireless communications system 100. Communications manager 101may transmit signaling to the UE 115 to maintain the control link withthe UE 115 and perform a second random-access procedure to re-establishthe control link with the UE 115 after the control link with the UE 115is lost. Communications manager 101 may also receive an uplinktransmission from the UE 115 to maintain the control link with the basestation 105.

An IRS UE 115 may include a communications manager 102. Communicationsmanager 102 may perform a first random-access procedure to establish acontrol link with a base station 105, the IRS UE 115 including areflective surface for forwarding signals from the base station 105 to adevice in wireless communications system 100. Communications manager 102may detect that the control link with the base station 105 is lost basedat least in part on a timer or counter expiring or based at least inpart on failing to receive signaling from the base station 105.Communications manager 102 may perform a second random-access procedureto re-establish the control link with the base station 105 based atleast in part on detecting that the control link with the base station105 is lost. Communications manager 102 may also transmit an uplinktransmission to the base station 105 to maintain the control link withthe base station 105.

FIG. 2 illustrates an example of a process flow 200 illustrating atwo-step random-access procedure in accordance with one or more aspectsof the present disclosure. Process flow 200 illustrates aspects oftechniques performed by a UE 115-a, which may be an example of a UE 115described with reference to FIG. 1 . Process flow 200 also illustratesaspects of techniques performed by a base station 105-a, which may be anexample of a base station 105 described with reference to FIG. 1 . At205, the base station 105-a may transmit random-access channel (RACH)configuration information to the UE 115-a in system information or inRRC signaling. The base station 105-a may also transmit asynchronization signal block (SSB) to the UE 115-a. The UE 115-a mayreceive the SSB and determine to connect to the base station 105-a. At210, the UE 115-a may transmit a RACH preamble (e.g., physical RACH(PRACH)) to the base station 105-a, and, at 215, the UE 115-a maytransmit a payload in a PUSCH to the base station 105-a. The UE 115-amay transmit the RACH preamble and the PUSCH payload in a firstrandom-access message (e.g., a MsgA) in the two-step random-accessprocedure.

At 220, the base station 105-a may decode the first random-accessmessage including the preamble and the PUSCH payload. The base station105-a may then transmit a second random-access message (e.g., arandom-access message B (MsgB) or random-access response (RAR)) to theUE 115-a in the two-step random-access procedure. In particular, at 225,the base station 105-a may transmit control information in a PDCCH(e.g., MsgB PDCCH) to the UE 115-a (e.g., using a cell radio networktemporary identifier (RNTI) (C-RNTI) or MsgB RNTI), and, at 230, thebase station 105-a may transmit data in a PDSCH (e.g., MsgB PDSCH) tothe UE 115-a (e.g., a success RAR). At 235, the UE 115-a may identify avalid timing alignment (TA) for communications with the base station105-a and valid PUCCH resources and timing for an uplink transmission tothe base station 105-a. At 240, the UE 115-a may then transmit HARQfeedback (e.g., an ACK or NACK) indicating whether the secondrandom-access message is received and successfully decoded by the UE115-a.

FIG. 3 illustrates an example of a process flow 300 illustrating afour-step random-access procedure in accordance with one or more aspectsof the present disclosure. Process flow 300 illustrates aspects oftechniques performed by a UE 115-b, which may be an example of a UE 115described with reference to FIGS. 1 and 2 . Process flow 300 alsoillustrates aspects of techniques performed by a base station 105-b,which may be an example of a base station 105 described with referenceto FIGS. 1 and 2 . At 305, the UE 115-b may transmit a random-accesspreamble to the base station 105-b in a first random-access message,and, at 310, the base station 105-b may transmit a second random-accessmessage (e.g., RAR) in response to the random-access preamble. At 315,the UE 115-b may transmit a third random-access message including ascheduled transmission (e.g., data) to the base station 105-b, and, at320, the base station 105-b may transmit a contention resolution messageto the UE 115-b indicating that the four-step random-access procedurewas successful.

FIG. 4 illustrates an example of an IRS 400 in accordance with one ormore aspects of the present disclosure. The IRS in FIG. 4 may be anenergy efficient environment controller and may reflect incoming signals405 from one device (e.g., a base station 105) to another device (e.g.,a UE 115 or a base station 105). The IRS may control the angle ofreflected signals 410 and may cast and extend the signal to an uncoveredregion in a wireless communications system (e.g., a region uncovered bya base station 105 due to blockage). The reflected pattern (e.g., timedivision duplex (TDD) pattern) may be further improved to offer bettercoverage with guidance from a base station 105. For instance, the basestation 105 may adjust the reflected angle or sweep of the reflectedangles to allow the IRS to redirect a transmission to another wirelessdevice. The IRS may include a minimum control unit design and mayoperate with low power (e.g., extreme low power). The IRS may also havelittle to no requirements for uplink communication. For instance, theIRS may be configured for full transmission and reception (e.g., similarto an IoT device), or the IRS may be configured for simple transmissionand full reception. Simple transmission may include PRACH-only, RACHonly (e.g., PRACH plus a Msg3 transmission or a random-access Message A(MsgA) transmission), RACH transmissions plus an ACK for Msg3, or RACHtransmissions plus an ACK for Msg3 and uplink keep-alive signaling.

FIG. 5 illustrates an example of a flow of communications 500 between abase station 105-c, an IRS 505, and a UE 115-c in accordance with one ormore aspects of the present disclosure. In the example of FIG. 5 , theremay be a closed loop for communications between the base station 105-c,the IRS 505, and the UE 115-c. The base station 105-c may transmit datato the IRS 505 on a data link through the IRS 505 (e.g., in the dataplane), such that the IRS 505 may reflect or otherwise relay the data tothe UE 115-c. The base station 105-c may also transmit controlinformation to the IRS 505 on a control link with the IRS 505 (e.g., inthe control plane) to configure the IRS 505 to forward the data to theUE 115-c. The UE 115-c may provide feedback to the base station 105-c onthe data forwarded by the IRS 505 (e.g., control signaling that closesthe loop). To facilitate the data and control signaling between the basestation 105-c, the IRS 505, and the UE 115-c, it may be appropriate forthe base station 105-c and the UE 115-c to establish a data link throughthe IRS 505 and for the base station 105-c and the IRS 505 to establisha control link (e.g., RACH to start and end the process). In some cases,however, it may be challenging for the IRS 505 to maintain the controllink with the base station 105-c (e.g., if the IRS 505 is set up forminimal communication with the base station 105-c). Wirelesscommunications system 100 may support efficient techniques for detectingwhen a control link between a UE 115 and a base station 105 is lost andfor recovering the control link.

FIG. 6 illustrates an example of a wireless communications system 600that supports control link for low-power and simplified transceiver inaccordance with one or more aspects of the present disclosure. Thewireless communications system 600 includes a UE 115-d, which may be anexample of a UE 115 described with reference to FIGS. 1-5 . The wirelesscommunications system 600 may also include an IRS 605, which may be anexample of an IRS as described with reference to FIGS. 1-5 . Thewireless communications system 600 also includes a base station 105-d,which may be an example of a base station 105 described with referenceto FIGS. 1-5 . The base station 105-d may provide communication coveragefor a coverage area 110-a. The wireless communications system 600 mayimplement aspects of wireless communications system 100. For example,the wireless communications system 600 may support efficient techniquesfor detecting when a control link between the UE 115-d and the basestation 105-d is lost and for recovering the control link.

In the example of FIG. 6 , a path (e.g., line-of-sight (LOS) path)between the base station 105-d and the UE 115-d may be obstructed orblocked. Thus, instead of transmitting downlink signals directly to theUE 115-d, the base station 105-d may transmit the downlink signals tothe IRS 605, and the IRS 605 may forward the downlink signals to the UE115-d (e.g., a non-LOS (NLOS) path). To ensure that the base station105-d is able to use the IRS 605 for forwarding signals to the UE 115-d(e.g., and other devices in the wireless communications system 600), theIRS 605 may indicate to the base station 105-d that the IRS 605 iscapable of forwarding signals to the UE 115-d (e.g., and other devices).Specifically, the IRS 605 may transmit an indication to the base station105-d that the IRS 605 includes a reflective surface for forwardingsignals from the base station 105-d to the UE 115-d (e.g., that the IRS605 is a low-power UE 115 capable of forwarding signals to otherdevices).

In one example, the IRS 605 may transmit a random-access preamble (e.g.,PRACH) to the base station 105-d indicating that the IRS 605 includesthe reflective surface. In this example, the base station 105-d mayconfigure a reserved pool of random-access preambles that indicate thata UE 115 is an IRS or includes an IRS. In another example, the IRS 605may transmit the indication that the IRS 605 includes the reflectivesurface in a random-access message as part of a random-access procedure.For instance, the IRS 605 may transmit the indication that the IRS 605includes the reflective surface in a first random-access message in atwo-step random-access procedure (e.g., indicated in a field in apayload of MsgA) or a third random-access message in a four-steprandom-access procedure (e.g., indicated in a field in the payload ofMsg3).

In yet another example, the IRS 605 may transmit the indication that theIRS 605 includes the reflective surface after the IRS 605 is connectedto the base station 105-d. For instance, the IRS 605 may transmit theindication that the IRS 605 includes the reflective surface in a controlmessage (e.g., RRC message) to the base station 105-d after performing arandom-access procedure (e.g., a PRACH or RACH procedure as describedwith reference to FIGS. 2 and 3 ). The control message may indicate thecapability of the IRS 605 (e.g., that the IRS 605 includes thereflective surface) to allow the IRS 605 to identify with the basestation 105-d. In this example, the IRS 605 may be assigned with areserved pool of random-access preambles for future connection.Specifically, the IRS 605 may transmit random-access preambles from thereserved pool to the base station 105-d in subsequent random-accessprocedures to indicate that the IRS 605 includes a reflective surfacefor forwarding signals from the base station 105-d to other devices. Thebase station 105-d may also indicate a C-RNTI to the IRS 605 that theIRS 605 may use for performing a contention-free random-access procedureto connect to the base station 105-d.

Using these examples, the IRS 605 may be able to identify with the basestation 105-d, and the base station 105-d may be aware that the IRS 605is an IRS (e.g., the base station 105-d may be able to differentiate theIRS 605 from another UE 115). In some cases, the IRS 605 may also have adifferent configuration capability from other UEs 115 (e.g., bandwidth,center frequency, command type, etc.), and it may also be appropriatefor the IRS 605 to indicate the configuration capability to the basestation 105-d (e.g., inform the base station 105-d for furtherguidance). Thus, as an example, the IRS 605 may transmit theconfiguration capability to the base station 105-d in a random-accessmessage in a random-access procedure (e.g., Msg3 in a four-steprandom-access procedure or the payload of MsgA in a two-steprandom-access procedure). That is, the IRS 605 may transmit anindication that the IRS 605 is capable of supporting someconfigurations, and the base station 105-d may configure the IRS forsubsequent communications (e.g., forwarding signals from the basestation 105-d to the UE 115-d) based on the configurations supported bythe IRS 605.

The IRS 605 may also transmit a trigger to the base station 105-d toactivate or deactivate a control procedure (e.g., using an additionalindicator embedded in Msg3 of a four-step random-access procedure or thepayload in MsgA of a two-step random-access procedure). The controlprocedure may include control signaling from the base station 105-d toconfigure the IRS 605 for forwarding signals to the UE 115-d. Inparticular, the base station 105-d may transmit a command to the IRS 605indicating parameters or configurations for forwarding signals from thebase station 105-d to the UE 115-d (e.g., in accordance with theconfigurations supported by the IRS 605). In some cases, the command maybe embedded in a fourth random-access message of a four-steprandom-access procedure (e.g., a random-access Message 4 (Msg4)) or in asecond random-access message of a two-step random-access procedure(e.g., payload in MsgB, where the IRS 605 may send HARQ feedback afterdecoding the MsgB). That is, the base station 105-d may transmit thecommand in a random-access message to the IRS 605 in a random-accessprocedure.

In one example, the base station 105-d may transmit an explicit commandto the IRS 605 (e.g., in a few bytes in a PDCCH or PDSCH) indicatingconfigurations or parameters for forwarding signals from the basestation 105-d to the UE 115-d. The configurations or parameters mayinclude a sweep pattern (e.g., an order or sequence of the reflectedangles at which the IRS forwards (or reflects) signals), sweep direction(e.g., the reflected angles at which the IRS forwards (or reflects)signals), center frequency, or bandwidth for forwarding signals from thebase station 105-d to the UE 115-d. In some cases, the base station105-d may also transmit a request for the IRS 605 to perform beamtraining to identify a suitable beam for forwarding signals to the UE115-d (e.g., to enable channel estimation). In such cases, the basestation 105-d may also configure the IRS 605 for a beam sweep (e.g.,based on a sweep pattern and sweep direction), and the IRS may performthe beam sweep (e.g., over an SSB time slot or with channel stateinformation reference signals (CSI-RSs). The beam sweep may refer totransmitting, forwarding, or reflecting signals at multiple reflectedangles or on multiple beams (i.e., sweeping though reflected angles orbeams). The UE 115-d may then transmit feedback to the base station105-d on the beam sweep (e.g., on the signals received in the beamsweep), and the base station 105-d may transmit configurations orparameters to the IRS for forwarding signals from the base station 105-dto the UE 115-d based on the feedback. That is, the explicit command maybe based on feedback from the UE 115-d.

In another example, the base station 105-d may transmit an implicitcommand to the IRS 605 (e.g., in a few bits in a PDCCH) to allow the IRS605 to identify suitable configurations or parameters for forwardingsignals from the base station 105-d to the UE 115-d. For instance, theimplicit command may indicate either positive (e.g., good) or negative(e.g., bad) feedback for signals forwarded by the IRS 605 to the UE115-d. In some cases, the UE 115-d may provide feedback to the basestation 105-d on signals received from the base station 105-d via theIRS 605, and the base station 105-d may indicate either positive ornegative feedback to the IRS 605 based on the feedback from the UE115-d. As an example, if the UE 115-d provides an ACK for a transmissionforwarded by the IRS to the UE 115-d, the base station 105-d maytransmit positive feedback to the IRS 605. Alternatively, if the UE115-d provides a NACK for a transmission forwarded by the IRS 605 to theUE 115-d, the base station 105-d may transmit negative feedback to theIRS 605. The implicit command providing positive or negative feedbackmay serve for reinforcement learning (RL) based IRS tuning, where theIRS 605 gradually learns how to serve the base station 105-d. That is,the IRS 605 may tune parameters for forwarding signals from the basestation 105-d to the UE 115-d based on the implicit command (e.g., oneor more rounds of positive or negative feedback).

In addition to identifying with the base station 105-d and establishinga control link with the base station 105-d (e.g., to receiveconfigurations and parameters for forwarding signals to the UE 115-d),it may be appropriate for the IRS 605 to maintain the control link withthe base station 105-d. That is, because the environment may change overtime (e.g., due to blockage between the base station 105-d and the UE115-d and even between the base station 105-d and the IRS 605 or betweenthe IRS 605 and the UE 115-d), it may be appropriate for the basestation 105-d to confirm that the IRS 605 is connected (e.g., alive) andis able to receive signals (e.g., control commands and data) from thebase station 105-d. The IRS 605 may use the techniques described hereinto detect when the control link with the base station 105-d is lost sothat the IRS 605 may initiate a random-access procedure to recover thecontrol link. Alternatively, the base station 105-d may detect when thecontrol link with the IRS 605 is lost and wait until the control link isre-established before transmitting signals to the IRS 605 for forwardingto the UE 115-d.

In one example, the base station 105-d may transmit indicatorsperiodically through PDCCH to the IRS 605 to maintain the control linkwith the IRS 605 (e.g., even in a long sleep period). An indicator mayalso indicate whether the control link with the IRS 605 is to beadjusted. Because the indicators may be periodic, the IRS 605 mayidentify when to expect each indicator, and the IRS 605 may keep countof a number of indicators missed from the base station 105-d. Forinstance, the IRS 605 may increment a counter for each indicator thatthe IRS 605 failed to receive from the base station 105-d. If thecounter overflows (e.g., the counter exceeds a threshold or expires),the IRS 605 may detect that the control link with the base station 105-dis lost. Alternatively, the IRS 605 may decrement a counter for eachindicator that the IRS 605 failed to receive from the base station105-d. If the counter reaches zero (e.g., the counter expires), the IRS605 may detect that the control link with the base station 105-d islost. Once the IRS 605 detects that the control link with the basestation 105-d is lost, the IRS 605 may perform a random-access procedure(e.g., restart a RACH process) to re-establish the control link with thebase station 105-d.

In another example, the IRS 605 may be configured with a period forwhich a control link with the base station 105-d is valid. That is, thecontrol link with the base station 105-d may be valid for the durationof a timer. After the timer overflows or expires, the IRS 605 may detectthat the control link with the base station 105-d is lost, and the IRS605 may perform a random-access procedure (e.g., restart a RACH process)to re-establish the control link with the base station 105-d. The basestation 105-d may also determine the duration of the timer so that thebase station 105-d may avoid transmitting signaling to the IRS 605 forforwarding to the UE 115-d after the timer expires (e.g., and before theIRS 605 performs a next random-access procedure). In this example (e.g.,and others), the IRS 605 may maintain a cell radio network temporaryidentifier (C-RNTI) for contention-free connection (e.g., to perform acontention-free random-access procedure to re-establish the control linkwith the base station 105-d).

In yet another example, the IRS 605 may detect whether the control linkwith the base station 105-d is lost using energy detection. That is, ifthe IRS 605 fails to detect energy from the base station 105-d for aduration of a timer (e.g., energy from control or data signaling), theIRS 605 may detect that the control link with the base station 105-d islost, and the IRS 605 may perform a random-access procedure (e.g.,restart a RACH process) to re-establish the control link with the basestation 105-d. That is, the IRS 605 may restart a cell-search when thetimer overflows. The IRS 605 may have limited radio frequency components(e.g., such as an analog to digital converter (ADC)) connected with asubset of units in the IRS 605, and the IRS 605 may use the radiofrequency components to detect the energy from the base station 105-d.

In yet another example, the IRS 605 may transmit uplink transmissions(e.g., similar to scheduling request (SR) transmissions) to the basestation 105-d to maintain the control link with the base station 105-d.In one example, the IRS 605 may be dynamically configured to transmit anuplink transmission in response to a downlink transmission (e.g., aspecific downlink packet). For instance, the IRS 605 may receivedownlink control information (DCI) from the base station 105-drequesting an uplink transmission from the IRS 605 in response to adownlink transmission (e.g., HARQ feedback, such as an ACK). Therequests for uplink transmissions from the IRS 605 may be used by thebase station 105-d to ensure that a controller at the IRS 605 is able toreceive commands from the base station 105-d. Alternatively, the IRS 605may be configured to transmit uplink transmissions periodically. If thebase station 105-d fails to receive a threshold number of uplinktransmissions from the UE 115-d (e.g., requested uplink transmissions orperiodic uplink transmission), the base station 105-d may detect thatthe control link with the UE 115-d is lost. The base station 105-d maythen wait until the control link with the UE 115-d is re-established(e.g., through a random-access procedure) before transmitting signals tothe IRS 605 for forwarding to the UE 115-d.

In some cases, the IRS 605 may also be configured with a few differentPRACH sequences (e.g., random-access preambles) to indicate a quantityof commands (e.g., control commands) received from the base station105-d. That is, each PRACH sequence may correspond to a quantity ofcommands received by the IRS 605, and the IRS 605 may increment acounter for each command received from the base station 105-d. In suchcases, the base station 105-d may request that the IRS 605 transmit aPRACH sequence to the base station 105-d indicating the quantity ofcommands received by the IRS 605. Alternatively, the IRS 605 maytransmit PRACH sequences periodically to the base station, each PRACHsequence indicating the quantity of commands received by the IRS 605. Ifthe base station 105-d determines that the quantity of commands receivedby the IRS 605 is less than the quantity of commands transmitted to theIRS 605 by a threshold amount, the base station 105-d may detect thatthe control link with the UE 115-d is lost. The base station 105-d maythen wait until the control link with the UE 115-d is re-established(e.g., through a random-access procedure) before transmitting signals tothe IRS 605 for forwarding to the UE 115-d.

FIG. 7 illustrates an example of a process flow 700 that supports acontrol link for a low-power and simplified transceiver in accordancewith one or more aspects of the present disclosure. Process flow 700illustrates aspects of techniques performed by a UE 115-e, which may bean example of a UE 115 that includes an IRS as described with referenceto FIGS. 1-6 . Process flow 700 also illustrates aspects of techniquesperformed by a base station 105-e, which may be an example of a basestation 105 described with reference to FIGS. 1-6 . Process flow 700 maysupport efficient techniques for detecting when a control link betweenthe UE 115-e and the base station 105-e is lost and recovering thecontrol link.

At 705, the UE 115-e may perform a first random-access procedure (e.g.,exchange random-access messages) to establish a control link with thebase station 105-e. In some cases, the base station 105-e may transmitone or more periodic indicators in a control channel (e.g., PDCCH) tothe UE 115-e to maintain a control link with the UE 115-e (e.g., at 710and at 715). In such cases, the UE 115-e may be configured to determinewhether the control link with the base station 105-e is lost based onthe one or more indicators. For instance, at 720, the UE 115-e maydetect that the control link with the base station 105-e is lost if theUE 115-e fails to receive one or more (e.g., a threshold quantity) ofthe indicators. In one example, the UE 115-e may increment a counterafter each periodic indicator that the UE 115-e failed to receive. Inthis example, the UE 115-e may detect that the control link with thebase station 105-e is lost when the counter exceeds a threshold (e.g.,when the counter expires). In another example, the UE 115-e maydecrement a counter after each periodic indicator that the UE 115-efailed to receive. In this example, the UE 115-e may detect that thecontrol link with the base station 105-e is lost when the counterreaches zero (e.g., when the counter expires). The UE 115-e may receivecontrol information from the base station 105-e indicating theperiodicity and time intervals to monitor for the periodic indicators(e.g., control information scheduling the periodic indicators).Alternatively, the periodicity and time intervals to monitor for theperiodic indicators may be preconfigured at the UE 115-e.

In other cases, at 720, the UE 115-e may detect that the control linkwith the base station 105-e is lost based on a timer. The UE 115-e mayreceive an indication of the duration of the timer from the base station105-e, or the duration of the timer may be preconfigured at the UE115-e. In some examples, if the base station 105-e is also running thetimer, the base station 105-e may avoid transmitting signals to the UE115-e for forwarding to other devices after the timer expires. In oneexample, the UE 115-e may detect that the control link with the basestation 105-e is lost based on failing to detect energy from the basestation 105-e for the duration of the timer. In this example, the UE115-e may restart the timer after detecting energy from the base station105-e. The UE 115-e may use limited radio frequency components tomonitor for energy from the base station 105-e. In another example, theUE 115-e may simply detect that the control link with the base stationis lost when the timer expires. That is, the control link between the UE115-e and the base station 105-e may be valid for the duration of thetimer, and, once the timer expires, the UE 115-e may detect that thecontrol link with the base station 105-e is lost. Once the UE 115-edetects that the control link with the base station 105-e is lost, at725, the UE 115-e may perform a second random-access procedure tore-establish the control link with the base station 105-e. In somecases, the UE 115-e may perform a contention-free random-accessprocedure using a C-RNTI to re-establish the control link with the basestation 105-e.

FIG. 8 illustrates an example of a process flow 800 that supportscontrol link for low-power and simplified transceiver in accordance withone or more aspects of the present disclosure. Process flow 800illustrates aspects of techniques performed by a UE 115-f, which may bean example of a UE 115 that includes an IRS as described with referenceto FIGS. 1-7 . Process flow 800 also illustrates aspects of techniquesperformed by a base station 105-f, which may be an example of a basestation 105 described with reference to FIGS. 1-7 . Process flow 800 maysupport efficient techniques for detecting when a control link betweenthe UE 115-f and the base station 105-f is lost and recovering thecontrol link.

At 805, the UE 115-f may perform a first random-access procedure (e.g.,exchange random-access messages) to establish a control link with thebase station 105-f In some cases, the UE 115-f may transmit one or moreuplink transmissions to the base station 105-f to maintain the controllink with the base station 105-f (e.g., at 810 and at 815). In someexamples, the one or more uplink transmissions may be scheduling request(SR) transmissions or transmissions similar to SR transmissions (e.g., aheartbeat signal (a few bits)). In some examples, the one or more uplinktransmissions may be periodic transmissions. An uplink transmission fromthe UE 115-f may also be in response to a downlink transmission from thebase station 105-f. For instance, the UE 115-f may receive a request forthe uplink transmission (e.g., ACK) in response to a downlinktransmission. The UE 115-f may then receive the downlink transmissionand transmit the uplink transmission in response to the downlinktransmission.

At 820, the base station 105-f may detect that the control link with theUE 115-f is lost based on the one or more uplink transmissions. Forexample, the base station 105-f may fail to receive one or more of theuplink transmissions (e.g., a threshold quantity of uplinktransmissions) from the UE 115-f, and the base station 105-f may detectthat the control link with the UE 115-f is lost based on failing toreceive the one or more uplink transmissions from the UE 115-f.Alternatively, the UE 115-f may transmit, and the base station 105-f mayreceive, a random-access preamble indicating a quantity of controlcommands that the UE 115-f received from the base station 105-f (e.g.,control commands (implicit or explicit) as described with reference toFIG. 6 ). The UE 115-f may transmit the random-access preamble as anuplink transmission in the one or more uplink transmissions describedabove. For example, the UE 115-f may periodically transmit random-accesspreambles each indicating a quantity of control commands received by theUE 115-f, or the UE 115-f may transmit a random-access preambleindicating a quantity of control commands received by the UE 115-f inresponse to a request from the base station 105-e.

The base station 105-f may then compare the quantity of control commandsreceived by the UE 115-f to an actual quantity of control commandstransmitted by the base station 105-f to the UE 115-f. If the actualquantity of control commands transmitted by the base station 105-fexceeds the quantity of control commands received by the UE 115-f by athreshold amount, the base station 105-f may detect that the controllink with the UE 115-f is lost. Once the base station 105-f detects thatthe control link with the UE 115-f is lost, the base station 105-f mayavoid transmitting downlink signals to the UE 115-f for forwarding toother devices until the UE performs a second random-access procedure tore-establish the control link with the base station 105-f. At 825, theUE 115-f and the base station 105-f may perform a second random-accessprocedure (e.g., exchange random-access messages) to re-establish thecontrol link. Then, the base station 105-f may continue transmittingdownlink signals to the UE 115-f for forwarding to other devices.

FIG. 9 illustrates an example of a flow of communications 500 between abase station 105-c, an IRS 905, and a UE 115-c in accordance with one ormore aspects of the present disclosure. In the example of FIG. 5 , theremay be a closed loop for communications between the base station 105-c,the IRS 905, and the UE 115-c. The base station 105-c may transmit datato the IRS 905 on a data link through the IRS 905 (e.g., in the dataplane), and the IRS 905 may forward the data to the UE 115-c. The basestation 105-c may also transmit control information to the IRS 905 on acontrol link with the IRS 905 (e.g., in the control plane) to configurethe IRS 905 to forward the data to the UE 115-c. In some cases, the UE115-c may provide feedback to the base station 105-c on the dataforwarded by the IRS 905 (e.g., control signaling that closes the loop).To facilitate the data and control signaling between the base station105-c, the IRS 905, and the UE 115-c, it may be appropriate for the basestation 105-c and the UE 115-c to establish a data link through the IRS905 and for the base station 105-c and the IRS 905 to establish acontrol link (e.g., RACH to start and end the process). However, if theIRS 905 uses a same procedure as other UEs 115 for connecting to thebase station 105-c, the base station 105-c may not be able todifferentiate the IRS 905 from other UEs 115. Wireless communicationssystem 100 may support efficient techniques for establishing aconnection between an IRS and a base station 105.

FIG. 10 illustrates an example of a wireless communications system 1000that supports a random-access procedure for a low-power and simplifiedtransceiver in accordance with as with one or more aspects of thepresent disclosure. The wireless communications system 1000 includes aUE 115-d, which may be examples of a UE 115 described with reference toFIGS. 1-5 . The wireless communications system 1000 also includes an IRS1005, which may be an example of an IRS described with reference toFIGS. 1-5 . The wireless communications system 1000 also includes a basestation 105-d, which may be an example of a base station 105 describedwith reference to FIGS. 1-5 . The base station 105-d may providecommunication coverage for a coverage area 110-a. The wirelesscommunications system 1000 may implement aspects of wirelesscommunications system 100. For example, the wireless communicationssystem 1000 may support efficient techniques for establishing aconnection between the IRS 1005 and the base station 105-d.

In the example of FIG. 10 , a path (e.g., line-of-sight (LOS) path)between the base station 105-d and the UE 115-d may be obstructed orblocked. Thus, instead of transmitting downlink signals directly to theUE 115-d, the base station 105-d may transmit the downlink signals tothe IRS 1005, and the IRS 1005 may forward the downlink signals to theUE 115-d (e.g., a non-LOS (NLOS) path). To ensure that the base station105-d is able to use the IRS 1005 for forwarding signals to the UE 115-d(e.g., and other devices in the wireless communications system 1000),the IRS 1005 may indicate to the base station 105-d that the IRS 1005 iscapable of forwarding signals to the UE 115-d (e.g., and other devices).Specifically, the IRS 1005 may transmit an indication to the basestation 105-d that the IRS 1005 includes a reflective surface forforwarding signals from the base station 105-d to the UE 115-d (e.g.,that the IRS 1005 is a low-power UE 115 capable of forwarding signals toother devices).

In one example, the IRS 1005 may transmit a random-access preamble(e.g., PRACH) to the base station 105-d indicating that the IRS 1005includes the reflective surface. In this example, the base station 105-dmay configure a reserved pool of random-access preambles that indicatethat a UE 115 is an IRS or includes an IRS. In another example, the IRS1005 may transmit the indication that the IRS 1005 includes thereflective surface in a random-access message as part of a random-accessprocedure. For instance, the IRS 1005 may transmit the indication thatthe IRS 1005 includes the reflective surface in a first random-accessmessage in a two-step random-access procedure (e.g., indicated in afield in the payload of MsgA) or a third random-access message in afour-step random-access procedure (e.g., indicated in a field in thepayload of Msg3).

In yet another example, the IRS 1005 may transmit the indication thatthe IRS 1005 includes the reflective surface after the IRS 1005 isconnected to the base station 105-d. For instance, the IRS 1005 maytransmit the indication that the IRS 1005 includes the reflectivesurface in a control message (e.g., RRC message) to the base station105-d after performing a random-access procedure (e.g., a PRACH or RACHprocedure as described with reference to FIGS. 2 and 3 ). The controlmessage may indicate the capability of the IRS 1005 (e.g., that the IRS1005 includes the reflective surface) to allow the IRS 1005 to identifywith the base station 105-d. In this example, the IRS 1005 may beassigned with a reserved pool of random-access preambles for futureconnection. Specifically, the IRS 1005 may transmit random-accesspreambles from the reserved pool to the base station 105-d in subsequentrandom-access procedures to indicate that the IRS 1005 includes areflective surface for forwarding signals from the base station 105-d toother devices. The base station 105-d may also indicate a C-RNTI to theIRS 1005 that the IRS 1005 may use for performing a contention-freerandom-access procedure to connect to the base station 105-d.

Using these examples, the IRS 1005 may be able to identify with the basestation 105-d, and the base station 105-d may be aware that the IRS 1005is an IRS (e.g., the base station 105-d may be able to differentiate theIRS 1005 from another UE 115). In some cases, the IRS 1005 may also havea different configuration capability from other UEs 115 (e.g.,bandwidth, center frequency, command type, etc.), and it may also beappropriate for the IRS 1005 to indicate the configuration capability tothe base station 105-d (e.g., inform the base station 105-d for furtherguidance). Thus, as an example, the IRS 1005 may transmit theconfiguration capability to the base station 105-d in a random-accessmessage in a random-access procedure (e.g., Msg3 in a four-steprandom-access procedure or the payload of MsgA in a two-steprandom-access procedure). That is, the IRS 1005 may transmit anindication that the IRS 1005 is capable of supporting someconfigurations, and the base station 105-d may configure the IRS forsubsequent communications (e.g., forwarding signals from the basestation 105-d to the UE 115-d) based on the configurations supported bythe IRS 1005.

The IRS 1005 may also transmit a trigger to the base station 105-d toactivate or deactivate a control procedure (e.g., using an additionalindicator embedded in Msg3 of a four-step random-access procedure or thepayload in MsgA of a two-step random-access procedure). The controlprocedure may include control signaling from the base station 105-d toconfigure the IRS 1005 for forwarding signals to the UE 115-d. Inparticular, the base station 105-d may transmit a command to the IRS1005 indicating parameters or configurations for forwarding signals fromthe base station 105-d to the UE 115-d (e.g., in accordance with theconfigurations supported by the IRS 1005). In some cases, the commandmay be embedded in a fourth random-access message of a four-steprandom-access procedure (e.g., Msg4) or in a second random-accessmessage of a two-step random-access procedure (e.g., payload in MsgB,where the IRS 1005 may send HARQ feedback after decoding the MsgB). Thatis, the base station 105-d may transmit the command in a random-accessmessage to the IRS 1005 in a random-access procedure.

In one example, the base station 105-d may transmit an explicit commandto the IRS 1005 (e.g., in a few bytes in a PDCCH or PDSCH) indicatingconfigurations or parameters for forwarding signals from the basestation 105-d to the UE 115-d. The configurations or parameters mayinclude a sweep pattern (e.g., an order or sequence of the reflectedangles at which the IRS forwards (or reflects) signals), sweep direction(e.g., the reflected angles at which the IRS forwards (or reflects)signals), center frequency, or bandwidth for forwarding signals from thebase station 105-d to the UE 115-d. In some cases, the base station105-d may also transmit a request for the IRS 1005 to perform beamtraining to identify a suitable beam for forwarding signals to the UE115-d (e.g., to enable channel estimation). In such cases, the basestation 105-d may also configure the IRS 1005 for a beam sweep (e.g.,based on a sweep pattern and sweep direction), and the IRS may performthe beam sweep (e.g., over an SSB time slot or with channel stateinformation reference signals (CSI-RSs). The beam sweep may refer totransmitting, forwarding, or reflecting signals at multiple reflectedangles or on multiple beams (i.e., sweeping though reflected angles orbeams). The UE 115-d may then transmit feedback to the base station105-d on the beam sweep (e.g., on the signals received in the beamsweep), and the base station 105-d may transmit configurations orparameters to the IRS for forwarding signals from the base station 105-dto the UE 115-d based on the feedback. That is, the explicit command maybe based on feedback from the UE 115-d.

In another example, the base station 105-d may transmit an implicitcommand to the IRS 1005 (e.g., in a few bits in a PDCCH) to allow theIRS 1005 to identify suitable configurations or parameters forforwarding signals from the base station 105-d to the UE 115-d. Forinstance, the implicit command may indicate either positive (e.g., good)or negative (e.g., bad) feedback for signals forwarded by the IRS 1005to the UE 115-d. In some cases, the UE 115-d may provide feedback to thebase station 105-d on signals received from the base station 105-d viathe IRS 1005, and the base station 105-d may indicate either positive ornegative feedback to the IRS 1005 based on the feedback from the UE115-d. As an example, if the UE 115-d provides an ACK for a transmissionforwarded by the IRS to the UE 115-d, the base station 105-d maytransmit positive feedback to the IRS 1005. Alternatively, if the UE115-d provides a NACK for a transmission forwarded by the IRS 1005 tothe UE 115-d, the base station 105-d may transmit negative feedback tothe IRS 1005. The implicit command providing positive or negativefeedback may serve for reinforcement learning (RL) based IRS tuning,where the IRS 1005 gradually learns how to serve the base station 105-d.That is, the IRS 1005 may tune parameters for forwarding signals fromthe base station 105-d to the UE 115-d based on the implicit command(e.g., one or more rounds of positive or negative feedback).

In addition to identifying with the base station 105-d and establishinga control link with the base station 105-d (e.g., to receiveconfigurations and parameters for forwarding signals to the UE 115-d),it may be appropriate for the IRS 1005 to forward signals for a datalink between the base station 105-d and the UE 115-d, such that the IRS1005 may receive the signals from the base station 105-d and relay thesignals to the UE 115-d. In some cases, control signaling and datasignaling from the base station 105-d to the IRS 1005 may be on the samecarrier. In other cases, however, control signaling from the basestation 105-d to the IRS 1005 (e.g., IRS controller) may be on a firstcarrier (e.g., FRX), and data signaling from the base station 105-d tothe IRS 1005 (e.g., IRS carrier) may be on a second, different carrier(e.g., FRY). Thus, commands from the base station 105-d may becarrier-specific (e.g., FR-specific). Further, establishing a controllink may not guarantee that the base station 105-d could discover thelocation of the IRS 1005. Accordingly, the base station 105-d and IRS1005 may use the techniques described herein to establish a data link.For example, the base station 105-d may use the techniques describedherein to select a beam for transmitting downlink signals to the IRS1005 for forwarding to the UE 115-d (e.g., identify the incident anglefrom the base station 105-d to the IRS 1005).

In one example, the base station 105-d may discover the IRS 1005 inspace without assistance from the IRS 1005 and may establish a data linkthrough the IRS 1005 (e.g., IRS operating at FR2 or FR4). For example,the base station 105-d may use the IRS 1005 to establish a data linkwith the UE 115-d, such that the IRS 1005 may reflect or otherwise relaysignals between the base station 105-d and the UE 115-d. In thisexample, the base station 105-d may transmit signals to the IRS 1005 forforwarding to the UE 115-d. For instance, the base station 105-d mayperform a beam sweep by transmitting signals on multiple beams to theIRS 1005 for forwarding to the UE 115-d. The base station 105-d may thenreceive feedback from the UE 115-d on the signals forwarded by the IRS1005 to the UE 115-d, and the base station 105-d may establish a datalink through the IRS 1005 based on the feedback. Specifically, the basestation 105-d may identify which of the beams used to transmit signalsto the IRS 1005 is associated with a highest quality based on thefeedback from the UE 115-d, and the base station 105-d may select thehighest quality beam for transmitting subsequent signals to the IRS 1005for forwarding to the UE 115-d.

In another example, the IRS 1005 may provide assistance (e.g.,information or operation) to the base station 105-d to allow the basestation 105-d to discover the IRS 1005 and establish a data link throughthe IRS 1005. For instance, if the control link and the data link are onthe same carrier, the base station 105-d may use the same beamidentified in the random-access procedure or a beam with a similartarget direction to the beam identified in the random-access procedureto transmit signals to the IRS 1005 for forwarding to the UE 115-d. Thebeam identified in the random-access procedure may correspond to the SSBreceived by the IRS 1005 that triggered the random-access procedure.That is, the incident angle for transmissions from the base station105-d to the UE 115-d may roughly be known (e.g., for beam-basedcommunication), so the SSB identified in the random-access procedure maybe used for IRS reflection (e.g., to transmit signals to the IRS 1005for reflection to the UE 115-d).

Alternatively, if the control link and data link are cross-carrier(e.g., the control link is in a lower band and the base station 105-dtransmits control signaling with an omni-directional antenna), the UE115-d may provide additional assistance to the base station 105-d toestablish the data link. In one example, the UE 115-d may report itslocation to the base station 105-d (e.g., in the two PRACH since the UE115-d may be mostly static in space). In this example, the base station105-d may identify a beam for transmitting signals to the IRS 1005 forforwarding to the UE 115-d based on the location of the IRS 1005. Inanother example, the base station 105-d may transmit downlink signals onmultiple beams to the IRS 1005, and the IRS 1005 may sweep through allthe reflected angles (e.g., forward the downlink signals at all thereflected angles), where one of the reflected angles may reflect thedownlink signals back to the base station 105-d to establish the datalink with the base station 105-d (e.g., the IRS 1005 may use itscapability and operate in a mirror mode to reflect the downlink signalsback to the base station 105-d). The base station 105-d may thenidentify which of the beams used to transmit signals to the IRS 1005 isassociated with a highest quality based on the reflected signals, andthe base station 105-d may select the highest quality beam fortransmitting subsequent signals to the IRS 1005 for forwarding to the UE115-d.

FIG. 11 illustrates an example of a process flow 1100 that supports arandom-access procedure for a low-power and simplified transceiver inaccordance with one or more aspects of the present disclosure. Processflow 1100 illustrates aspects of techniques performed by a UE 115-e,which may be an example of a UE 115 described with reference to FIGS.1-10 . Process flow 1100 also illustrates aspects of techniquesperformed by a base station 105-e, which may be an example of a basestation 105 described with reference to FIGS. 1-10 . Process flow 1100may support efficient techniques for establishing a connection betweenthe UE 115-e that includes an IRS and the base station 105-e.

At 1105, the UE 115-e may transmit a random-access preamble (e.g.,PRACH) to the base station 105-e to initiate a random-access procedureto connect to the base station 105-e. At 1110, the UE 115-e may thentransmit an indication to the base station 105-e that the UE 115-eincludes an IRS. In some cases, the random-access preamble may indicatethat the UE 115-e includes the IRS, and the UE 115-e may avoidtransmitting an additional indication at 1110. In such cases, the UE115-e may be configured with one or more random-access preamblesreserved for indicating that the UE 115-e includes the IRS. In othercases, the UE 115-e may transmit the indication that the UE 115-eincludes the IRS in a first random-access message (e.g., MsgA) in atwo-step random-access procedure. In yet other cases, the UE 115-e maytransmit the indication that the UE 115-e includes the IRS in a thirdrandom-access message (e.g., Msg3) in a four-step random-accessprocedure. In yet other cases, the UE 115-e may transmit the indicationthat the UE 115-e includes the IRS in a control message (e.g., RRCmessage) after the random-access procedure. In such cases, the UE 115-emay receive an indication of one or more random-access preamblesreserved for indicating that the UE 115-e includes the IRS. As such, forsubsequent random-access procedures, the UE 115-e may transmit arandom-access preamble of the one or more random-access preambles toindicate that the UE 115-e includes the IRS.

At 1115, the base station 105-e may identify a configuration for the UE115-e to forward signals to another device (e.g., a UE 115 or a basestation 105). At 1120, the base station 105-e may then transmit acommand configuring the UE 115-e for forwarding signals to otherdevices. In one example, the command (e.g., explicit command) mayindicate a sweep pattern, sweep direction, center frequency, bandwidth,or a combination thereof for the IRS to use to forward signals from thebase station 105-e to another device. In another example, the command(e.g., implicit command) may indicate either positive or negativefeedback for signals from the base station 105-e forwarded by the UE115-e to another wireless device. In this example, the UE 115-e may tuneparameters for forwarding signals from the base station 105-e to thewireless device based on the command.

At 1125, the UE 115-e may communicate with the base station 105-e toestablish a data link. For example, the UE 115-e may communicate withthe base station 105-e to allow the base station 105-e to identify anappropriate beam for transmitting signals to the UE 115-e for forwardingto another device. In one example, the UE 115-e may transmit anindication of the location of the UE 115-e to the base station 105-e,and the base station 105-e may select a beam for transmitting signals tothe UE 115-e for forwarding to another device based on the location ofthe UE. In another example, the base station 105-e may transmit signalsto the UE 115-e on multiple beams, and the UE 115-e may reflect thesignals back to the base station 105-e at a same angle at which thesignals are transmitted to the UE 115-e on the multiple beams. In thisexample, the base station 105-e may identify a beam of the multiplebeams associated with a highest quality based on the reflection, and thebase station 105-e may select the identified beam for transmittingsignals to the UE 115-e for forwarding to another wireless device. Inyet another example, the base station 105-e may select a beam identifiedin the random-access procedure (e.g., initiated at 1105) fortransmitting signals to the UE 115-e for forwarding to another wirelessdevice.

At 1130, the UE 115-e may receive downlink signals from the base station105-e for forwarding from the base station 105-e to another device(e.g., a UE 115 or base station 105). The UE 115-e may then forward thedownlink signals to the other device. In some cases, the base station105-e may receive feedback from the other device on the signalsforwarded by the UE 115-e from the base station 105-e to the otherdevice. In such cases, the base station 105-e may adjust a configurationat the UE 115-e for forwarding signals to the other device based on thefeedback. For example, the base station 105-e may transmit anothercommand (e.g., similar to the command at 1120) to configure the UE 115-efor forwarding signals to the wireless device. The base station 105-emay also adjust a configuration for transmitting signals to the UE 115-efor forwarding signals to the other device based on the feedback.

FIG. 12 shows a block diagram 1200 of a device 1205 that supportscontrol link for low-power and simplified transceiver in accordance withone or more aspects of the present disclosure. The device 1205 may be anexample of aspects of a UE 115 as described herein. The device 1205 mayinclude a receiver 1210, a communications manager 1215, and atransmitter 1220. The device 1205 may also include a processor. Each ofthese components may be in communication with one another (e.g., via oneor more buses).

The receiver 1210 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to control linkfor low-power and simplified transceiver, etc.). Information may bepassed on to other components of the device 1205. The receiver 1210 maybe an example of aspects of the transceiver 1520 described withreference to FIG. 15 . The receiver 1210 may utilize a single antenna ora set of antennas.

The communications manager 1215 may perform a first random-accessprocedure to establish a control link with a base station, the UEincluding a reflective surface for forwarding signals from the basestation to a device in a wireless network, detect that the control linkwith the base station is lost based on a timer or counter expiring orbased on failing to receive signaling from the base station, and performa second random-access procedure to re-establish the control link withthe base station based on detecting that the control link with the basestation is lost. The communications manager 1215 may also perform afirst random-access procedure to establish a control link with a basestation, the UE including a reflective surface for forwarding signalsfrom the base station to a device in a wireless network and transmit anuplink transmission to the base station to maintain the control linkwith the base station.

The communications manager 1215, or its sub-components, may beimplemented in hardware, code (e.g., software or firmware) executed by aprocessor, or any combination thereof. If implemented in code executedby a processor, the functions of the communications manager 1215, or itssub-components may be executed by a general-purpose processor, a digitalsignal processor (DSP), an application-specific integrated circuit(ASIC), a field-programmable gate array (FPGA) or other programmablelogic device, discrete gate or transistor logic, discrete hardwarecomponents, or any combination thereof designed to perform the functionsdescribed in the present disclosure.

The communications manager 1215, or its sub-components, may bephysically located at various positions, including being distributedsuch that portions of functions are implemented at different physicallocations by one or more physical components. In some examples, thecommunications manager 1215, or its sub-components, may be a separateand distinct component in accordance with various aspects of the presentdisclosure. In some examples, the communications manager 1215, or itssub-components, may be combined with one or more other hardwarecomponents, including but not limited to an input/output (I/O)component, a transceiver, a network server, another computing device,one or more other components described in the present disclosure, or acombination thereof in accordance with various aspects of the presentdisclosure.

The transmitter 1220 may transmit signals generated by other componentsof the device 1205. In some examples, the transmitter 1220 may becollocated with a receiver 1210 in a transceiver module. For example,the transmitter 1220 may be an example of aspects of the transceiver1520 described with reference to FIG. 15 . The transmitter 1220 mayutilize a single antenna or a set of antennas.

The communications manager 1215 may be an example of means forperforming various aspects of control link management for low-power orsimplified transceivers as described herein. The communications manager1215, or its sub-components, may be implemented in hardware (e.g., incommunications management circuitry). The circuitry may comprise of aprocessor, a digital signal processor (DSP), an application-specificintegrated circuit (ASIC), a field-programmable gate array (FPGA) orother programmable logic devices, discrete gate or transistor logic,discrete hardware components, or any combination thereof designed toperform the functions described in the present disclosure.

In another implementation, the communications manager 1215, or itssub-components, may be implemented in code (e.g., as communicationsmanagement software or firmware) executed by a processor, or anycombination thereof. If implemented in code executed by a processor, thefunctions of the communications manager 1215, or its sub-components maybe executed by a general-purpose processor, a DSP, an ASIC, a FPGA, orother programmable logic devices.

In some examples, the communication manager 1215 may be configured toperform various operations (e.g., establishing, receiving, detecting,re-establishing, transmitting, etc.) using or otherwise in cooperationwith the receiver 1210, the transmitter 1220, or both.

FIG. 13 shows a block diagram 1300 of a device 1305 that supportscontrol link for low-power and simplified transceiver in accordance withone or more aspects of the present disclosure. The device 1305 may be anexample of aspects of a device 1205, or a UE 115 as described herein.The device 1305 may include a receiver 1310, a communications manager1315, and a transmitter 1330. The device 1305 may also include aprocessor. Each of these components may be in communication with oneanother (e.g., via one or more buses).

The receiver 1310 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to control linkfor low-power and simplified transceiver, etc.). Information may bepassed on to other components of the device 1305. The receiver 1310 maybe an example of aspects of the transceiver 1520 described withreference to FIG. 15 . The receiver 1310 may utilize a single antenna ora set of antennas.

The communications manager 1315 may be an example of aspects of thecommunications manager 1215 as described herein. The communicationsmanager 1315 may include a random-access manager 1320 and a control linkmanager 1325. The communications manager 1315 may be an example ofaspects of the communications manager 1215 described herein.

The random-access manager 1320 may perform a first random-accessprocedure to establish a control link with a base station, the UEincluding a reflective surface for forwarding signals from the basestation to a device in a wireless network. The control link manager 1325may detect that the control link with the base station is lost based ona timer or counter expiring or based on failing to receive signalingfrom the base station. The random-access manager 1320 may perform asecond random-access procedure to re-establish the control link with thebase station based on detecting that the control link with the basestation is lost.

The random-access manager 1320 may perform a first random-accessprocedure to establish a control link with a base station, the UEincluding a reflective surface for forwarding signals from the basestation to a device in a wireless network. The control link manager 1325may transmit an uplink transmission to the base station to maintain thecontrol link with the base station.

The transmitter 1330 may transmit signals generated by other componentsof the device 1305. In some examples, the transmitter 1330 may becollocated with a receiver 1310 in a transceiver module. For example,the transmitter 1330 may be an example of aspects of the transceiver1520 described with reference to FIG. 15 . The transmitter 1330 mayutilize a single antenna or a set of antennas.

FIG. 14 shows a block diagram 1400 of a communications manager 1405 thatsupports control link for low-power and simplified transceiver inaccordance with one or more aspects of the present disclosure. Thecommunications manager 1405 may be an example of aspects of acommunications manager 1215, a communications manager 1315, or acommunications manager 1510 described herein. The communications manager1405 may include a random-access manager 1410, a control link manager1415, a counter 1420, an energy detector 1425, an uplink request manager1430, and a downlink manager 1435. Each of these modules maycommunicate, directly or indirectly, with one another (e.g., via one ormore buses).

The random-access manager 1410 may perform a first random-accessprocedure to establish a control link with a base station, the UEincluding a reflective surface for forwarding signals from the basestation to a device in a wireless network. The control link manager 1415may detect that the control link with the base station is lost based ona timer or counter expiring or based on failing to receive signalingfrom the base station. In some examples, the random-access manager 1410may perform a second random-access procedure to re-establish the controllink with the base station based on detecting that the control link withthe base station is lost.

In some examples, the control link manager 1415 may fail to receive oneor more periodic indicators in a control channel, where detecting thatthe control link with the base station is lost is based on failing toreceive the one or more periodic indicators in the control channel. Thecounter 1420 may increment after failing to receive each of the one ormore periodic indicators in the control channel, where detecting thatthe control link with the base station is lost is based on the counterexceeding a threshold. In some examples, the counter 1420 may decrementafter failing to receive each of the one or more periodic indicators inthe control channel, where detecting that the control link with the basestation is lost is based on the counter reaching zero.

In some examples, the control link manager 1415 may identify that thecontrol link with the base station is valid for a duration of the timer,where detecting that the control link with the base station is lost isbased on the timer expiring. The energy detector 1425 may fail to detectenergy from the base station for a duration of the timer, wheredetecting that the control link with the base station is lost is basedon failing to detect the energy from the base station for the durationof the timer. In some examples, the control link manager 1415 mayrestart the timer after detecting energy from the base station. In someexamples, the random-access manager 1410 may perform a contention-freerandom-access procedure using a C-RNTI to re-establish the control linkwith the base station.

In some examples, the random-access manager 1410 may perform a firstrandom-access procedure to establish a control link with a base station,the UE including a reflective surface for forwarding signals from thebase station to a device in a wireless network. In some examples, thecontrol link manager 1415 may transmit an uplink transmission to thebase station to maintain the control link with the base station. In somecases, the uplink transmission includes a scheduling request. In somecases, the uplink transmission includes a periodic uplink transmission.The uplink request manager 1430 may receive a request for the uplinktransmission from the UE in response to a downlink transmission. Thedownlink manager 1435 may receive the downlink transmission from thebase station, where the uplink transmission is received in response tothe downlink transmission. In some examples, the random-access manager1410 may transmit a random-access preamble indicating a quantity ofcontrol commands received from the base station.

FIG. 15 shows a diagram of a system 1500 including a device 1505 thatsupports control link for low-power and simplified transceiver inaccordance with one or more aspects of the present disclosure. Thedevice 1505 may be an example of or include the components of device1205, device 1305, or a UE 115 as described herein. The device 1505 mayinclude components for bi-directional voice and data communicationsincluding components for transmitting and receiving communications,including a communications manager 1510, an I/O controller 1515, atransceiver 1520, an antenna 1525, memory 1530, and a processor 1540.These components may be in electronic communication via one or morebuses (e.g., bus 1545).

The communications manager 1510 may perform a first random-accessprocedure to establish a control link with a base station, the UEincluding a reflective surface for forwarding signals from the basestation to a device in a wireless network, detect that the control linkwith the base station is lost based on a timer or counter expiring orbased on failing to receive signaling from the base station, and performa second random-access procedure to re-establish the control link withthe base station based on detecting that the control link with the basestation is lost. The communications manager 1510 may also perform afirst random-access procedure to establish a control link with a basestation, the UE including a reflective surface for forwarding signalsfrom the base station to a device in a wireless network and transmit anuplink transmission to the base station to maintain the control linkwith the base station.

The I/O controller 1515 may manage input and output signals for thedevice 1205. The I/O controller 1515 may also manage peripherals notintegrated into the device 1205. In some cases, the I/O controller 1515may represent a physical connection or port to an external peripheral.In some cases, the I/O controller 1515 may utilize an operating systemsuch as iOS®, ANDROID®, MS-DOS®, MS-WINDOWS®, OS/2®, UNIX®, LINUX®, oranother known operating system. In other cases, the I/O controller 1515may represent or interact with a modem, a keyboard, a mouse, atouchscreen, or a similar device. In some cases, the I/O controller 1515may be implemented as part of a processor. In some cases, a user mayinteract with the device 1205 via the I/O controller 1515 or viahardware components controlled by the I/O controller 1515.

The transceiver 1520 may communicate bi-directionally, via one or moreantennas, wired, or wireless links as described above. For example, thetransceiver 1520 may represent a wireless transceiver and maycommunicate bi-directionally with another wireless transceiver. Thetransceiver 1520 may also include a modem to modulate the packets andprovide the modulated packets to the antennas for transmission, and todemodulate packets received from the antennas.

In some cases, the wireless device may include a single antenna 1525.However, in some cases the device may have more than one antenna 1525,which may be capable of concurrently transmitting or receiving multiplewireless transmissions.

The memory 1530 may include random-access memory (RAM) and read-onlymemory (ROM). The memory 1530 may store computer-readable,computer-executable code 1535 including instructions that, whenexecuted, cause the processor to perform various functions describedherein. In some cases, the memory 1530 may contain, among other things,a basic input/output system (BIOS) which may control basic hardware orsoftware operation such as the interaction with peripheral components ordevices.

The processor 1540 may include an intelligent hardware device, (e.g., ageneral-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, anFPGA, a programmable logic device, a discrete gate or transistor logiccomponent, a discrete hardware component, or any combination thereof).In some cases, the processor 1540 may be configured to operate a memoryarray using a memory controller. In other cases, a memory controller maybe integrated into the processor 1540. The processor 1540 may beconfigured to execute computer-readable instructions stored in a memory(e.g., the memory 1530) to cause the device 1205 to perform variousfunctions (e.g., functions or tasks supporting control link forlow-power and simplified transceiver).

The code 1535 may include instructions to implement aspects of thepresent disclosure, including instructions to support wirelesscommunications. The code 1535 may be stored in a non-transitorycomputer-readable medium such as system memory or other type of memory.In some cases, the code 1535 may not be directly executable by theprocessor 1540 but may cause a computer (e.g., when compiled andexecuted) to perform functions described herein.

FIG. 16 shows a block diagram 1600 of a device 1605 that supportscontrol link for low-power and simplified transceiver in accordance withone or more aspects of the present disclosure. The device 1605 may be anexample of aspects of a base station 105 as described herein. The device1605 may include a receiver 1610, a communications manager 1615, and atransmitter 1620. The device 1605 may also include a processor. Each ofthese components may be in communication with one another (e.g., via oneor more buses).

The receiver 1610 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to control linkfor low-power and simplified transceiver, etc.). Information may bepassed on to other components of the device 1605. The receiver 1610 maybe an example of aspects of the transceiver 1920 described withreference to FIG. 19 . The receiver 1610 may utilize a single antenna ora set of antennas.

The communications manager 1615 may perform a first random-accessprocedure to establish a control link with a UE, the UE including areflective surface for forwarding signals from the base station to adevice in a wireless network, transmit signaling to the UE to maintainthe control link with the UE, and perform a second random-accessprocedure to re-establish the control link with the UE after the controllink with the UE is lost. The communications manager 1615 may alsoperform a first random-access procedure to establish a control link witha UE, the UE including a reflective surface for forwarding signals fromthe base station to a device in a wireless network and receive an uplinktransmission from the UE to maintain the control link with the basestation. The communications manager 1615 may be an example of aspects ofthe communications manager 1910 described herein.

The communications manager 1615, or its sub-components, may beimplemented in hardware, code (e.g., software or firmware) executed by aprocessor, or any combination thereof. If implemented in code executedby a processor, the functions of the communications manager 1615, or itssub-components may be executed by a general-purpose processor, a DSP, anapplication-specific integrated circuit (ASIC), an FPGA or otherprogrammable logic device, discrete gate or transistor logic, discretehardware components, or any combination thereof designed to perform thefunctions described in the present disclosure.

The communications manager 1615, or its sub-components, may bephysically located at various positions, including being distributedsuch that portions of functions are implemented at different physicallocations by one or more physical components. In some examples, thecommunications manager 1615, or its sub-components, may be a separateand distinct component in accordance with various aspects of the presentdisclosure. In some examples, the communications manager 1615, or itssub-components, may be combined with one or more other hardwarecomponents, including but not limited to an input/output (I/O)component, a transceiver, a network server, another computing device,one or more other components described in the present disclosure, or acombination thereof in accordance with various aspects of the presentdisclosure.

The transmitter 1620 may transmit signals generated by other componentsof the device 1605. In some examples, the transmitter 1620 may becollocated with a receiver 1610 in a transceiver module. For example,the transmitter 1620 may be an example of aspects of the transceiver1920 described with reference to FIG. 19 . The transmitter 1620 mayutilize a single antenna or a set of antennas.

The communications manager 1615 may be an example of means forperforming various aspects of control link management for low-power orsimplified transceivers as described herein. The communications manager1615, or its sub-components, may be implemented in hardware (e.g., incommunications management circuitry). The circuitry may comprise of aprocessor, a DSP, an ASIC, an FPGA or other programmable logic devices,discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described in thepresent disclosure.

In another implementation, the communications manager 1615, or itssub-components, may be implemented in code (e.g., as communicationsmanagement software or firmware) executed by a processor, or anycombination thereof. If implemented in code executed by a processor, thefunctions of the communications manager 1615, or its sub-components maybe executed by a general-purpose processor, a DSP, an ASIC, a FPGA, orother programmable logic devices.

In some examples, the communication manager 1615 may be configured toperform various operations (e.g., establishing, receiving, detecting,re-establishing, transmitting, etc.) using or otherwise in cooperationwith the receiver 1610, the transmitter 1620, or both.

FIG. 17 shows a block diagram 1700 of a device 1705 that supportscontrol link for low-power and simplified transceiver in accordance withone or more aspects of the present disclosure. The device 1705 may be anexample of aspects of a device 1605, or a base station 105 as describedherein. The device 1705 may include a receiver 1710, a communicationsmanager 1715, and a transmitter 1730. The device 1705 may also include aprocessor. Each of these components may be in communication with oneanother (e.g., via one or more buses).

The receiver 1710 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to control linkfor low-power and simplified transceiver, etc.). Information may bepassed on to other components of the device 1705. The receiver 1710 maybe an example of aspects of the transceiver 1920 described withreference to FIG. 19 . The receiver 1710 may utilize a single antenna ora set of antennas.

The communications manager 1715 may be an example of aspects of thecommunications manager 1715 as described herein. The communicationsmanager 1715 may include a random-access manager 1720 and a control linkmanager 1725. The communications manager 1715 may be an example ofaspects of the communications manager 1910 described herein.

The random-access manager 1720 may perform a first random-accessprocedure to establish a control link with a UE, the UE including areflective surface for forwarding signals from the base station to adevice in a wireless network. The control link manager 1725 may transmitsignaling to the UE to maintain the control link with the UE. Therandom-access manager 1720 may perform a second random-access procedureto re-establish the control link with the UE after the control link withthe UE is lost.

The random-access manager 1720 may perform a first random-accessprocedure to establish a control link with a UE, the UE including areflective surface for forwarding signals from the base station to adevice in a wireless network. The control link manager 1725 may receivean uplink transmission from the UE to maintain the control link with thebase station.

The transmitter 1730 may transmit signals generated by other componentsof the device 1705. In some examples, the transmitter 1730 may becollocated with a receiver 1710 in a transceiver module. For example,the transmitter 1730 may be an example of aspects of the transceiver1920 described with reference to FIG. 19 . The transmitter 1730 mayutilize a single antenna or a set of antennas.

FIG. 18 shows a block diagram 1800 of a communications manager 1805 thatsupports control link for low-power and simplified transceiver inaccordance with one or more aspects of the present disclosure. Thecommunications manager 1805 may be an example of aspects of acommunications manager 1615, a communications manager 1715, or acommunications manager 1910 described herein. The communications manager1805 may include a random-access manager 1810, a control link manager1815, a downlink manager 1820, and an uplink request manager 1825. Eachof these modules may communicate, directly or indirectly, with oneanother (e.g., via one or more buses).

The random-access manager 1810 may perform a first random-accessprocedure to establish a control link with a UE, the UE including areflective surface for forwarding signals from the base station to adevice in a wireless network. The control link manager 1815 may transmitsignaling to the UE to maintain the control link with the UE. In someexamples, the random-access manager 1810 may perform a secondrandom-access procedure to re-establish the control link with the UEafter the control link with the UE is lost. In some examples, thecontrol link manager 1815 may transmit one or more periodic indicatorsin a control channel to the base station, where the control link withthe UE is lost when the UE fails to receive a threshold number of theone or more periodic indicators. In some examples, the random-accessmanager 1810 may perform a contention-free random-access procedure usinga C-RNTI to re-establish the control link with the UE.

In some examples, the random-access manager 1810 may perform a firstrandom-access procedure to establish a control link with a UE, the UEincluding a reflective surface for forwarding signals from the basestation to a device in a wireless network. In some examples, the controllink manager 1815 may receive an uplink transmission from the UE tomaintain the control link with the base station. In some examples, thecontrol link manager 1815 may fail to receive one or more uplinktransmissions from the UE. In some examples, the control link manager1815 may detect that the control link with the UE is lost based onfailing to receive the one or more uplink transmissions from the UE. Thedownlink manager 1820 may avoid transmitting downlink signals to the UEfor forwarding to the device in the wireless network until the UEperforms a second random-access procedure to re-establish the controllink with the base station. In some cases, the uplink transmissionincludes a scheduling request. In some cases, the uplink transmissionincludes a periodic uplink transmission.

The uplink request manager 1825 may transmit a request for the uplinktransmission from the UE in response to a downlink transmission. In someexamples, the downlink manager 1820 may transmit the downlinktransmission to the UE, where the uplink transmission is received inresponse to the downlink transmission. In some examples, therandom-access manager 1810 may receive a random-access preambleindicating a first quantity of control commands received from the basestation. In some examples, the control link manager 1815 may determinethat a second quantity of control commands transmitted by the basestation exceeds the first quantity of control commands received by theUE by a threshold amount. In some examples, the control link manager1815 may detect that the control link with the UE is lost based on thedetermining. In some examples, the downlink manager 1820 may avoidtransmitting downlink signals to the UE for forwarding to the device inthe wireless network until the UE performs a second random-accessprocedure to re-establish the control link with the base station.

FIG. 19 shows a diagram of a system 1900 including a device 1905 thatsupports control link for low-power and simplified transceiver inaccordance with one or more aspects of the present disclosure. Thedevice 1905 may be an example of or include the components of device1605, device 1705, or a base station 105 as described herein. The device1905 may include components for bi-directional voice and datacommunications including components for transmitting and receivingcommunications, including a communications manager 1910, a networkcommunications manager 1915, a transceiver 1920, an antenna 1925, memory1930, a processor 1940, and an inter-station communications manager1945. These components may be in electronic communication via one ormore buses (e.g., bus 1950).

The communications manager 1910 may perform a first random-accessprocedure to establish a control link with a UE, the UE including areflective surface for forwarding signals from the base station to adevice in a wireless network, transmit signaling to the UE to maintainthe control link with the UE, and perform a second random-accessprocedure to re-establish the control link with the UE after the controllink with the UE is lost. The communications manager 1910 may alsoperform a first random-access procedure to establish a control link witha UE, the UE including a reflective surface for forwarding signals fromthe base station to a device in a wireless network and receive an uplinktransmission from the UE to maintain the control link with the basestation.

The network communications manager 1915 may manage communications withthe core network (e.g., via one or more wired backhaul links). Forexample, the network communications manager 1915 may manage the transferof data communications for client devices, such as one or more UEs 115.

The transceiver 1920 may communicate bi-directionally, via one or moreantennas, wired, or wireless links as described above. For example, thetransceiver 1920 may represent a wireless transceiver and maycommunicate bi-directionally with another wireless transceiver. Thetransceiver 1920 may also include a modem to modulate the packets andprovide the modulated packets to the antennas for transmission, and todemodulate packets received from the antennas.

In some cases, the wireless device may include a single antenna 1925.However, in some cases the device may have more than one antenna 1925,which may be capable of concurrently transmitting or receiving multiplewireless transmissions.

The memory 1930 may include RAM, ROM, or a combination thereof. Thememory 1930 may store computer-readable code 1935 including instructionsthat, when executed by a processor (e.g., the processor 1940) cause thedevice to perform various functions described herein. In some cases, thememory 1930 may contain, among other things, a BIOS which may controlbasic hardware or software operation such as the interaction withperipheral components or devices.

The processor 1940 may include an intelligent hardware device, (e.g., ageneral-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, anFPGA, a programmable logic device, a discrete gate or transistor logiccomponent, a discrete hardware component, or any combination thereof).In some cases, the processor 1940 may be configured to operate a memoryarray using a memory controller. In some cases, a memory controller maybe integrated into processor 1940. The processor 1940 may be configuredto execute computer-readable instructions stored in a memory (e.g., thememory 1930) to cause the device 1605 to perform various functions(e.g., functions or tasks supporting control link for low-power andsimplified transceiver).

The inter-station communications manager 1945 may manage communicationswith other base station 105, and may include a controller or schedulerfor controlling communications with UEs 115 in cooperation with otherbase stations 105. For example, the inter-station communications manager1945 may coordinate scheduling for transmissions to UEs 115 for variousinterference mitigation techniques such as beamforming or jointtransmission. In some examples, the inter-station communications manager1945 may provide an X2 interface within an LTE/LTE-A wirelesscommunication network technology to provide communication between basestations 105.

The code 1935 may include instructions to implement aspects of thepresent disclosure, including instructions to support wirelesscommunications. The code 1935 may be stored in a non-transitorycomputer-readable medium such as system memory or other type of memory.In some cases, the code 1935 may not be directly executable by theprocessor 1940 but may cause a computer (e.g., when compiled andexecuted) to perform functions described herein.

FIG. 20 shows a block diagram 2000 of a device 2005 that supportsrandom-access procedure for low-power and simplified transceiver inaccordance with one or more aspects of the present disclosure. Thedevice 2005 may be an example of aspects of a UE 115 as describedherein. The device 2005 may include a receiver 2010, a communicationsmanager 2015, and a transmitter 2020. The device 2005 may also include aprocessor. Each of these components may be in communication with oneanother (e.g., via one or more buses).

The receiver 2010 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related torandom-access procedure for low-power and simplified transceiver, etc.).Information may be passed on to other components of the device 2005. Thereceiver 2010 may be an example of aspects of the transceiver 2320described with reference to FIG. 23 . The receiver 2010 may utilize asingle antenna or a set of antennas.

The communications manager 2015 may initiate a random-access procedureto connect to a base station, transmit, to the base station, anindication that the UE includes a reflective surface for forwardingsignals from the base station to a device in a wireless network, andreceive signals from the base station for forwarding to the device inthe wireless network based on transmitting the indication. Thecommunications manager 2015 may be an example of aspects of thecommunications manager 2310 described herein.

The communications manager 2015, or its sub-components, may beimplemented in hardware, code (e.g., software or firmware) executed by aprocessor, or any combination thereof. If implemented in code executedby a processor, the functions of the communications manager 2015, or itssub-components may be executed by a general-purpose processor, a digitalsignal processor (DSP), an application-specific integrated circuit(ASIC), a field-programmable gate array (FPGA) or other programmablelogic device, discrete gate or transistor logic, discrete hardwarecomponents, or any combination thereof designed to perform the functionsdescribed in the present disclosure.

The communications manager 2015, or its sub-components, may bephysically located at various positions, including being distributedsuch that portions of functions are implemented at different physicallocations by one or more physical components. In some examples, thecommunications manager 2015, or its sub-components, may be a separateand distinct component in accordance with various aspects of the presentdisclosure. In some examples, the communications manager 2015, or itssub-components, may be combined with one or more other hardwarecomponents, including but not limited to an input/output (I/O)component, a transceiver, a network server, another computing device,one or more other components described in the present disclosure, or acombination thereof in accordance with various aspects of the presentdisclosure.

The transmitter 2020 may transmit signals generated by other componentsof the device 2005. In some examples, the transmitter 2020 may becollocated with a receiver 2010 in a transceiver module. For example,the transmitter 2020 may be an example of aspects of the transceiver2320 described with reference to FIG. 23 . The transmitter 2020 mayutilize a single antenna or a set of antennas.

FIG. 21 shows a block diagram 2100 of a device 2105 that supportsrandom-access procedure for low-power and simplified transceiver inaccordance with one or more aspects of the present disclosure. Thedevice 2105 may be an example of aspects of a device 2005, or a UE 115as described herein. The device 2105 may include a receiver 2110, acommunications manager 2115, and a transmitter 2135. The device 2105 mayalso include a processor. Each of these components may be incommunication with one another (e.g., via one or more buses).

The receiver 2110 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related torandom-access procedure for low-power and simplified transceiver, etc.).Information may be passed on to other components of the device 2105. Thereceiver 2110 may be an example of aspects of the transceiver 2320described with reference to FIG. 23 . The receiver 2110 may utilize asingle antenna or a set of antennas.

The communications manager 2115 may be an example of aspects of thecommunications manager 2015 as described herein. The communicationsmanager 2115 may include a random-access manager 2120, a capabilitymanager 2125, and a forwarding manager 2130. The communications manager2115 may be an example of aspects of the communications manager 2310described herein.

The random-access manager 2120 may initiate a random-access procedure toconnect to a base station. The capability manager 2125 may transmit, tothe base station, an indication that the UE includes a reflectivesurface for forwarding signals from the base station to a device in awireless network. The forwarding manager 2130 may receive signals fromthe base station for forwarding to the device in the wireless networkbased on transmitting the indication.

The transmitter 2135 may transmit signals generated by other componentsof the device 2105. In some examples, the transmitter 2135 may becollocated with a receiver 2110 in a transceiver module. For example,the transmitter 2135 may be an example of aspects of the transceiver2320 described with reference to FIG. 23 . The transmitter 2135 mayutilize a single antenna or a set of antennas.

FIG. 22 shows a block diagram 2200 of a communications manager 2205 thatsupports random-access procedure for low-power and simplifiedtransceiver in accordance with one or more aspects of the presentdisclosure. The communications manager 2205 may be an example of aspectsof a communications manager 2015, a communications manager 2115, or acommunications manager 2310 described herein. The communications manager2205 may include a random-access manager 2210, a capability manager2215, a forwarding manager 2220, a RRC manager 2225, a configurationmanager 2230, a feedback manager 2235, a location manager 2240, and areflector 2245. Each of these modules may communicate, directly orindirectly, with one another (e.g., via one or more buses).

The random-access manager 2210 may initiate a random-access procedure toconnect to a base station. The capability manager 2215 may transmit, tothe base station, an indication that the UE includes a reflectivesurface for forwarding signals from the base station to a device in awireless network. The forwarding manager 2220 may receive signals fromthe base station for forwarding to the device in the wireless networkbased on transmitting the indication.

In some examples, the random-access manager 2210 may transmit arandom-access preamble indicating that the UE includes the reflectivesurface. In some examples, the random-access manager 2210 may identifythe random-access preamble from one or more random-access preamblesreserved for indicating that the UE includes the reflective surface. Insome examples, the random-access manager 2210 may transmit a firstrandom-access message in a two-step random-access procedure includingthe indication that the UE includes the reflective surface. In someexamples, the random-access manager 2210 may transmit a thirdrandom-access message in a four-step random-access procedure includingthe indication that the UE includes the reflective surface. The RRCmanager 2225 may transmit, after the random-access procedure, an RRCmessage indicating that the UE includes the reflective surface.

In some examples, the random-access manager 2210 may receive anindication of one or more random-access preambles reserved forindicating that the UE includes the reflective surface. In someexamples, the random-access manager 2210 may transmit, as part of asubsequent random-access procedure, a random-access preamble of the oneor more random-access preambles indicating that the UE includes thereflective surface. The configuration manager 2230 may receive, from thebase station, a command indicating a sweep pattern, sweep direction,center frequency, bandwidth, or a combination thereof for forwardingsignals from the base station to the device in the wireless network. Insome examples, the forwarding manager 2220 may forward signals from thebase station to the device in the wireless network based on receivingthe command.

The feedback manager 2235 may receive, from the base station, a commandindicating positive or negative feedback for signals forwarded from thebase station to the device in the wireless network. In some examples,the configuration manager 2230 may tune parameters for forwardingsignals from the base station to the device in the wireless networkbased on the command. In some examples, the forwarding manager 2220 mayforward signals from the base station to the device in the wirelessnetwork based on the tuning. The location manager 2240 may transmit anindication of a location of the device in the wireless network to thebase station. The reflector 2245 may receive one or more signals fromthe base station, and the reflector 2245 may reflect the one or moresignals back to the base station at a same angle at which the one ormore signals are received. In some cases, the UE includes a low-power UEand the reflective surface includes an IRS.

FIG. 23 shows a diagram of a system 2300 including a device 2305 thatsupports random-access procedure for low-power and simplifiedtransceiver in accordance with one or more aspects of the presentdisclosure. The device 2305 may be an example of or include thecomponents of device 2005, device 2105, or a UE 115 as described herein.The device 2305 may include components for bi-directional voice and datacommunications including components for transmitting and receivingcommunications, including a communications manager 2310, an I/Ocontroller 2315, a transceiver 2320, an antenna 2325, memory 2330, and aprocessor 2340. These components may be in electronic communication viaone or more buses (e.g., bus 2345).

The communications manager 2310 may initiate a random-access procedureto connect to a base station, transmit, to the base station, anindication that the UE includes a reflective surface for forwardingsignals from the base station to a device in a wireless network, andreceive signals from the base station for forwarding to the device inthe wireless network based on transmitting the indication.

The I/O controller 2315 may manage input and output signals for thedevice 2305. The I/O controller 2315 may also manage peripherals notintegrated into the device 2305. In some cases, the I/O controller 2315may represent a physical connection or port to an external peripheral.In some cases, the I/O controller 2315 may utilize an operating systemsuch as iOS®, ANDROID®, MS-DOS®, MS-WINDOWS®, OS/2®, UNIX®, LINUX®, oranother known operating system. In other cases, the I/O controller 2315may represent or interact with a modem, a keyboard, a mouse, atouchscreen, or a similar device. In some cases, the I/O controller 2315may be implemented as part of a processor. In some cases, a user mayinteract with the device 2305 via the I/O controller 2315 or viahardware components controlled by the I/O controller 2315.

The transceiver 2320 may communicate bi-directionally, via one or moreantennas, wired, or wireless links as described above. For example, thetransceiver 2320 may represent a wireless transceiver and maycommunicate bi-directionally with another wireless transceiver. Thetransceiver 2320 may also include a modem to modulate the packets andprovide the modulated packets to the antennas for transmission, and todemodulate packets received from the antennas.

In some cases, the wireless device may include a single antenna 2325.However, in some cases the device may have more than one antenna 2325,which may be capable of concurrently transmitting or receiving multiplewireless transmissions.

The memory 2330 may include random-access memory (RAM) and read-onlymemory (ROM). The memory 2330 may store computer-readable,computer-executable code 1135 including instructions that, whenexecuted, cause the processor to perform various functions describedherein. In some cases, the memory 2330 may contain, among other things,a basic input/output system (BIOS) which may control basic hardware orsoftware operation such as the interaction with peripheral components ordevices.

The processor 2340 may include an intelligent hardware device, (e.g., ageneral-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, anFPGA, a programmable logic device, a discrete gate or transistor logiccomponent, a discrete hardware component, or any combination thereof).In some cases, the processor 2340 may be configured to operate a memoryarray using a memory controller. In other cases, a memory controller maybe integrated into the processor 2340. The processor 2340 may beconfigured to execute computer-readable instructions stored in a memory(e.g., the memory 2330) to cause the device 2305 to perform variousfunctions (e.g., functions or tasks supporting random-access procedurefor low-power and simplified transceiver).

The code 2335 may include instructions to implement aspects of thepresent disclosure, including instructions to support wirelesscommunications. The code 2335 may be stored in a non-transitorycomputer-readable medium such as system memory or other type of memory.In some cases, the code 2335 may not be directly executable by theprocessor 2340 but may cause a computer (e.g., when compiled andexecuted) to perform functions described herein.

FIG. 24 shows a block diagram 2400 of a device 2405 that supportsrandom-access procedure for low-power and simplified transceiver inaccordance with one or more aspects of the present disclosure. Thedevice 2405 may be an example of aspects of a base station 105 asdescribed herein. The device 2405 may include a receiver 2410, acommunications manager 2415, and a transmitter 2420. The device 2405 mayalso include a processor. Each of these components may be incommunication with one another (e.g., via one or more buses).

The receiver 2410 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related torandom-access procedure for low-power and simplified transceiver, etc.).Information may be passed on to other components of the device 2405. Thereceiver 2410 may be an example of aspects of the transceiver 1520described with reference to FIG. 15 . The receiver 2410 may utilize asingle antenna or a set of antennas.

The communications manager 2415 may receive, from a UE, an indicationthat the UE includes a reflective surface for forwarding signals fromthe base station to a device in a wireless network and transmit signalsto the UE for forwarding to the device in the wireless network based onreceiving the indication. The communications manager 2415 may be anexample of aspects of the communications manager 1510 described herein.

The communications manager 2415, or its sub-components, may beimplemented in hardware, code (e.g., software or firmware) executed by aprocessor, or any combination thereof. If implemented in code executedby a processor, the functions of the communications manager 2415, or itssub-components may be executed by a general-purpose processor, a DSP, anapplication-specific integrated circuit (ASIC), an FPGA or otherprogrammable logic device, discrete gate or transistor logic, discretehardware components, or any combination thereof designed to perform thefunctions described in the present disclosure.

The communications manager 2415, or its sub-components, may bephysically located at various positions, including being distributedsuch that portions of functions are implemented at different physicallocations by one or more physical components. In some examples, thecommunications manager 2415, or its sub-components, may be a separateand distinct component in accordance with various aspects of the presentdisclosure. In some examples, the communications manager 2415, or itssub-components, may be combined with one or more other hardwarecomponents, including but not limited to an input/output (I/O)component, a transceiver, a network server, another computing device,one or more other components described in the present disclosure, or acombination thereof in accordance with various aspects of the presentdisclosure.

The transmitter 2420 may transmit signals generated by other componentsof the device 2405. In some examples, the transmitter 2420 may becollocated with a receiver 2410 in a transceiver module. For example,the transmitter 2420 may be an example of aspects of the transceiver2720 described with reference to FIG. 27 . The transmitter 2420 mayutilize a single antenna or a set of antennas.

FIG. 25 shows a block diagram 2500 of a device 2505 that supportsrandom-access procedure for low-power and simplified transceiver inaccordance with one or more aspects of the present disclosure. Thedevice 2505 may be an example of aspects of a device 2405, or a basestation 105 as described herein. The device 2505 may include a receiver2510, a communications manager 2515, and a transmitter 2530. The device2505 may also include a processor. Each of these components may be incommunication with one another (e.g., via one or more buses).

The receiver 2510 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related torandom-access procedure for low-power and simplified transceiver, etc.).Information may be passed on to other components of the device 2505. Thereceiver 2510 may be an example of aspects of the transceiver 2720described with reference to FIG. 27 . The receiver 2510 may utilize asingle antenna or a set of antennas.

The communications manager 2515 may be an example of aspects of thecommunications manager 2415 as described herein. The communicationsmanager 2515 may include a capability manager 2520 and a forwardingmanager 2525. The communications manager 2515 may be an example ofaspects of the communications manager 2710 described herein.

The capability manager 2520 may receive, from a UE, an indication thatthe UE includes a reflective surface for forwarding signals from thebase station to a device in a wireless network. The forwarding manager2525 may transmit signals to the UE for forwarding to the device in thewireless network based on receiving the indication.

The transmitter 2530 may transmit signals generated by other componentsof the device 2505. In some examples, the transmitter 2530 may becollocated with a receiver 2510 in a transceiver module. For example,the transmitter 2530 may be an example of aspects of the transceiver2720 described with reference to FIG. 27 . The transmitter 2530 mayutilize a single antenna or a set of antennas.

FIG. 26 shows a block diagram 2600 of a communications manager 2605 thatsupports random-access procedure for low-power and simplifiedtransceiver in accordance with one or more aspects of the presentdisclosure. The communications manager 2605 may be an example of aspectsof a communications manager 2415, a communications manager 2515, or acommunications manager 2710 described herein. The communications manager2605 may include a capability manager 2610, a forwarding manager 2615, arandom-access manager 2620, a RRC manager 2625, a configuration manager2630, a feedback manager 2635, a beam manager 2640, a location manager2645, and a reflection manager 2650. Each of these modules maycommunicate, directly or indirectly, with one another (e.g., via one ormore buses).

The capability manager 2610 may receive, from a UE, an indication thatthe UE includes a reflective surface for forwarding signals from thebase station to a device in a wireless network. The forwarding manager2615 may transmit signals to the UE for forwarding to the device in thewireless network based on receiving the indication. The random-accessmanager 2620 may receive a random-access preamble indicating that the UEincludes the reflective surface. In some examples, receiving a firstrandom-access message in a two-step random-access procedure includingthe indication that the UE includes the reflective surface. In someexamples, receiving a third random-access message in a four-steprandom-access procedure including the indication that the UE includesthe reflective surface. The RRC manager 2625 may receive, after arandom-access procedure, an RRC message indicating that the UE includesthe reflective surface.

In some examples, the random-access manager 2620 may transmit to the UE,an indication of one or more random-access preambles reserved forindicating that the UE includes the reflective surface. In someexamples, the random-access manager 2620 may receive, from the UE aspart of a subsequent random-access procedure, a random-access preambleof the one or more random-access preambles indicating that the UEincludes the reflective surface. The configuration manager 2630 maytransmit, to the UE, a command indicating a sweep pattern, sweepdirection, center frequency, bandwidth, or a combination thereof forforwarding signals from the base station to the device in the wirelessnetwork. The feedback manager 2635 may receive, from the device in thewireless network, feedback on signals forwarded by the UE from the basestation to the device in the wireless network, where transmitting thecommand is based on the received feedback.

In some examples, the feedback manager 2635 may receive, from the devicein the wireless network, feedback on signals forwarded by the UE fromthe base station to the device in the wireless network. In someexamples, the feedback manager 2635 may transmit, to the UE, a commandindicating positive or negative feedback for signals forwarded from thebase station to the device in the wireless network based on receivingthe feedback. In some examples, the forwarding manager 2615 maytransmit, to the UE on a set of beams, a set of signals for forwardingto the device in the wireless network. In some examples, the feedbackmanager 2635 may receive, from the device in the wireless network,feedback on the set of signals forwarded by the UE from the base stationto the device in the wireless network. The beam manager 2640 mayidentify a beam of the set of beams associated with a highest qualitybased on the received feedback. In some examples, the beam manager 2640may select the identified beam for transmitting signals to the UE forforwarding to the device in the wireless network.

The location manager 2645 may receive an indication of a location of theUE. In some examples, the beam manager 2640 may select a beam fortransmitting signals to the UE for forwarding to the device in thewireless network based on the location of the UE. In some examples, thebeam manager 2640 may transmit a set of signals to the UE on a set ofbeams. The reflection manager 2650 may receive a reflection of the setof signals from the UE at a same angle at which the set of signals aretransmitted to the UE on the set of beams. In some examples, the beammanager 2640 may identify a beam of the set of beams associated with ahighest quality based on receiving the reflection. In some examples, thebeam manager 2640 may select the identified beam for transmittingsignals to the UE for forwarding to the device in the wireless network.In some examples, the beam manager 2640 may select a beam identified inthe random-access procedure for transmitting signals to the UE forforwarding to the device in the wireless network. In some cases, the UEincludes a low-power UE and the reflective surface includes an IRS.

FIG. 27 shows a diagram of a system 2700 including a device 2705 thatsupports random-access procedure for low-power and simplifiedtransceiver in accordance with one or more aspects of the presentdisclosure. The device 2705 may be an example of or include thecomponents of device 2405, device 2505, or a base station 105 asdescribed herein. The device 1505 may include components forbi-directional voice and data communications including components fortransmitting and receiving communications, including a communicationsmanager 2710, a network communications manager 2715, a transceiver 2720,an antenna 2725, memory 2730, a processor 2740, and an inter-stationcommunications manager 2745. These components may be in electroniccommunication via one or more buses (e.g., bus 2750).

The communications manager 2710 may receive, from a UE, an indicationthat the UE includes a reflective surface for forwarding signals fromthe base station to a device in a wireless network and transmit signalsto the UE for forwarding to the device in the wireless network based onreceiving the indication.

The network communications manager 2715 may manage communications withthe core network (e.g., via one or more wired backhaul links). Forexample, the network communications manager 2715 may manage the transferof data communications for client devices, such as one or more UEs 115.

The transceiver 2720 may communicate bi-directionally, via one or moreantennas, wired, or wireless links as described above. For example, thetransceiver 2720 may represent a wireless transceiver and maycommunicate bi-directionally with another wireless transceiver. Thetransceiver 2720 may also include a modem to modulate the packets andprovide the modulated packets to the antennas for transmission, and todemodulate packets received from the antennas.

In some cases, the wireless device may include a single antenna 2725.However, in some cases the device may have more than one antenna 2725,which may be capable of concurrently transmitting or receiving multiplewireless transmissions.

The memory 2730 may include RAM, ROM, or a combination thereof. Thememory 2730 may store computer-readable code 2735 including instructionsthat, when executed by a processor (e.g., the processor 2740) cause thedevice to perform various functions described herein. In some cases, thememory 2730 may contain, among other things, a BIOS which may controlbasic hardware or software operation such as the interaction withperipheral components or devices.

The processor 2740 may include an intelligent hardware device, (e.g., ageneral-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, anFPGA, a programmable logic device, a discrete gate or transistor logiccomponent, a discrete hardware component, or any combination thereof).In some cases, the processor 2740 may be configured to operate a memoryarray using a memory controller. In some cases, a memory controller maybe integrated into processor 2740. The processor 2740 may be configuredto execute computer-readable instructions stored in a memory (e.g., thememory 2730) to cause the device 2705 to perform various functions(e.g., functions or tasks supporting random-access procedure forlow-power and simplified transceiver).

The inter-station communications manager 2745 may manage communicationswith other base station 105, and may include a controller or schedulerfor controlling communications with UEs 115 in cooperation with otherbase stations 105. For example, the inter-station communications manager2745 may coordinate scheduling for transmissions to UEs 115 for variousinterference mitigation techniques such as beamforming or jointtransmission. In some examples, the inter-station communications manager2745 may provide an X2 interface within an LTE/LTE-A wirelesscommunication network technology to provide communication between basestations 105.

The code 2735 may include instructions to implement aspects of thepresent disclosure, including instructions to support wirelesscommunications. The code 2735 may be stored in a non-transitorycomputer-readable medium such as system memory or other type of memory.In some cases, the code 2735 may not be directly executable by theprocessor 2740 but may cause a computer (e.g., when compiled andexecuted) to perform functions described herein.

FIG. 28 shows a flowchart illustrating a method 2800 that supportscontrol link for low-power and simplified transceiver in accordance withaspects of the present disclosure. The operations of the method 2800 maybe implemented by a UE or its components as described herein. Forexample, the operations of the method 2800 may be performed by a UE 115as described with reference to FIGS. 1 through 15 and 20 through 23 . Insome examples, a UE may execute a set of instructions to control thefunctional elements of the UE to perform the described functions.Additionally or alternatively, the UE may perform aspects of thedescribed functions using special-purpose hardware.

At 2805, the method may include establishing a first link with the basestation based on a first random access procedure, the first linkincluding a control link associated with controlling a state of thefirst device, the first device including a reflective surface forforwarding signals associated with a second link from the base stationto a second device in a wireless network. The operations of 2805 may beperformed in accordance with examples as disclosed herein. In someexamples, aspects of the operations of 2805 may be performed by controllink manager 1415 as described with reference to FIG. 14 .

At 2810, the method may include detecting that the first link with thebase station is lost based on a timer or counter expiring or based onfailing to receive signaling from the base station. The operations of2810 may be performed in accordance with examples as disclosed herein.In some examples, aspects of the operations of 2810 may be performed bycontrol link manager 1415 as described with reference to FIG. 14 .

At 2815, the method may include re-establishing the first link with thebase station based on detecting that the first link with the basestation is lost, the first link re-established based on a second randomaccess procedure. The operations of 2815 may be performed in accordancewith examples as disclosed herein. In some examples, aspects of theoperations of 2815 may be performed by control link manager 1415 asdescribed with reference to FIG. 14 .

FIG. 29 shows a flowchart illustrating a method 2900 that supportscontrol link for low-power and simplified transceiver in accordance withaspects of the present disclosure. The operations of the method 2900 maybe implemented by a UE or its components as described herein. Forexample, the operations of the method 2900 may be performed by a UE 115as described with reference to FIGS. 1 through 15 and 20 through 23 . Insome examples, a UE may execute a set of instructions to control thefunctional elements of the UE to perform the described functions.Additionally or alternatively, the UE may perform aspects of thedescribed functions using special-purpose hardware.

At 2905, the method may include transmitting, to the base station, arandom-access preamble including an indication that the first deviceincludes the reflective surface, the random-access preamble initiating afirst random-access procedure with the base station. The operations of2905 may be performed in accordance with examples as disclosed herein.In some examples, aspects of the operations of 2905 may be performed bycontrol link manager 1415 as described with reference to FIG. 14 .

At 2910, the method may include establishing a first link with the basestation based on the first random access procedure, the first linkincluding a control link associated with controlling a state of thefirst device, the first device including a reflective surface forforwarding signals associated with a second link from the base stationto a second device in a wireless network. The operations of 2910 may beperformed in accordance with examples as disclosed herein. In someexamples, aspects of the operations of 2910 may be performed by controllink manager 1415 as described with reference to FIG. 14 .

At 2915, the method may include detecting that the first link with thebase station is lost based on a timer or counter expiring or based onfailing to receive signaling from the base station. The operations of2915 may be performed in accordance with examples as disclosed herein.In some examples, aspects of the operations of 2915 may be performed bycontrol link manager 1415 as described with reference to FIG. 14 .

At 2920, the method may include re-establishing the first link with thebase station based on detecting that the first link with the basestation is lost, the first link re-established based on a second randomaccess procedure. The operations of 2920 may be performed in accordancewith examples as disclosed herein. In some examples, aspects of theoperations of 2920 may be performed by control link manager 1415 asdescribed with reference to FIG. 14 .

FIG. 30 shows a flowchart illustrating a method 3000 that supportscontrol link for low-power and simplified transceiver in accordance withaspects of the present disclosure. The operations of the method 3000 maybe implemented by a base station or its components as described herein.For example, the operations of the method 3000 may be performed by abase station 105 as described with reference to FIGS. 1 through 11, 16through 19, and 24 through 27 . In some examples, a base station mayexecute a set of instructions to control the functional elements of thebase station to perform the described functions. Additionally oralternatively, the base station may perform aspects of the describedfunctions using special-purpose hardware.

At 3005, the method may include establishing a first link with a firstdevice based on a first random-access procedure, the first linkincluding a control link associated with controlling a state of thefirst device, the first device including a reflective surface forforwarding signals associated with a second link from the base stationto a second device in a wireless network. The operations of 3005 may beperformed in accordance with examples as disclosed herein. In someexamples, aspects of the operations of 3005 may be performed by controllink manager 1815 as described with reference to FIG. 18 .

At 3010, the method may include transmitting signaling to the firstdevice to maintain the first link with the first device. The operationsof 3010 may be performed in accordance with examples as disclosedherein. In some examples, aspects of the operations of 3010 may beperformed by control link manager 1815 as described with reference toFIG. 18 .

At 3015, the method may include performing a second random-accessprocedure to re-establish the first link with the first device after thefirst link with the first device is lost. The operations of 3015 may beperformed in accordance with examples as disclosed herein. In someexamples, aspects of the operations of 3015 may be performed by controllink manager 1815 as described with reference to FIG. 18 .

FIG. 31 shows a flowchart illustrating a method 3100 that supportscontrol link for low-power and simplified transceiver in accordance withaspects of the present disclosure. The operations of the method 3100 maybe implemented by a base station or its components as described herein.For example, the operations of the method 3100 may be performed by abase station 105 as described with reference to FIGS. 1 through 11, 16through 19, and 24 through 27 . In some examples, a base station mayexecute a set of instructions to control the functional elements of thebase station to perform the described functions. Additionally oralternatively, the base station may perform aspects of the describedfunctions using special-purpose hardware.

At 3105, the method may include receiving, from a first device, arandom-access preamble including an indication that the first deviceincludes the reflective surface, the random-access preamble initiating afirst random-access procedure with the first device. The operations of3105 may be performed in accordance with examples as disclosed herein.In some examples, aspects of the operations of 3105 may be performed bycontrol link manager 1815 as described with reference to FIG. 18 .

At 3110, the method may include establishing a first link with a firstdevice based on the first random-access procedure, the first linkincluding a control link associated with controlling a state of thefirst device, the first device including a reflective surface forforwarding signals associated with a second link from the base stationto a second device in a wireless network. The operations of 3110 may beperformed in accordance with examples as disclosed herein. In someexamples, aspects of the operations of 3110 may be performed by controllink manager 1815 as described with reference to FIG. 18 .

At 3115, the method may include transmitting signaling to the firstdevice to maintain the first link with the first device. The operationsof 3115 may be performed in accordance with examples as disclosedherein. In some examples, aspects of the operations of 3115 may beperformed by control link manager 1815 as described with reference toFIG. 18 .

At 3120, the method may include performing a second random-accessprocedure to re-establish the first link with the first device after thefirst link with the first device is lost. The operations of 3120 may beperformed in accordance with examples as disclosed herein. In someexamples, aspects of the operations of 3120 may be performed by controllink manager 1815 as described with reference to FIG. 18 .

FIG. 32 shows a flowchart illustrating a method 3200 that supportscontrol link for low-power and simplified transceiver in accordance withaspects of the present disclosure. The operations of the method 3200 maybe implemented by a UE or its components as described herein. Forexample, the operations of the method 3200 may be performed by a UE 115as described with reference to FIGS. 1 through 15 and 20 through 23 . Insome examples, a UE may execute a set of instructions to control thefunctional elements of the UE to perform the described functions.Additionally or alternatively, the UE may perform aspects of thedescribed functions using special-purpose hardware.

At 3205, the method may include establishing a first link with a basestation based on a first random-access procedure, the first linkincluding a control link associated with controlling a state of thefirst device, the first device including a reflective surface forforwarding signals associated with a second link from the base stationto a second device in a wireless network. The operations of 3205 may beperformed in accordance with examples as disclosed herein. In someexamples, aspects of the operations of 3205 may be performed by controllink manager 1415 as described with reference to FIG. 14 .

At 3210, the method may include transmitting an uplink transmission tothe base station to maintain the first link with the base station. Theoperations of 3210 may be performed in accordance with examples asdisclosed herein. In some examples, aspects of the operations of 3210may be performed by control link manager 1415 as described withreference to FIG. 14 .

FIG. 33 shows a flowchart illustrating a method 3300 that supportscontrol link for low-power and simplified transceiver in accordance withaspects of the present disclosure. The operations of the method 3300 maybe implemented by a UE or its components as described herein. Forexample, the operations of the method 3300 may be performed by a UE 115as described with reference to FIGS. 1 through 15 and 20 through 23 . Insome examples, a UE may execute a set of instructions to control thefunctional elements of the UE to perform the described functions.Additionally or alternatively, the UE may perform aspects of thedescribed functions using special-purpose hardware.

At 3305, the method may include transmitting, to the base station, arandom-access preamble including an indication that the first deviceincludes a reflective surface, the random-access preamble initiating afirst random-access procedure with the base station. The operations of3305 may be performed in accordance with examples as disclosed herein.In some examples, aspects of the operations of 3305 may be performed bycontrol link manager 1415 as described with reference to FIG. 14 .

At 3310, the method may include establishing a first link with a basestation based on the first random-access procedure, the first linkincluding a control link associated with controlling a state of thefirst device, the first device including a reflective surface forforwarding signals associated with a second link from the base stationto a second device in a wireless network. The operations of 3310 may beperformed in accordance with examples as disclosed herein. In someexamples, aspects of the operations of 3310 may be performed by controllink manager 1415 as described with reference to FIG. 14 .

At 3315, the method may include transmitting an uplink transmission tothe base station to maintain the first link with the base station. Theoperations of 3315 may be performed in accordance with examples asdisclosed herein. In some examples, aspects of the operations of 3315may be performed by control link manager 1415 as described withreference to FIG. 14 .

FIG. 34 shows a flowchart illustrating a method 3400 that supportscontrol link for low-power and simplified transceiver in accordance withaspects of the present disclosure. The operations of the method 3400 maybe implemented by a base station or its components as described herein.For example, the operations of the method 3400 may be performed by abase station 105 as described with reference to FIGS. 1 through 11, 16through 19, and 24 through 27 . In some examples, a base station mayexecute a set of instructions to control the functional elements of thebase station to perform the described functions. Additionally oralternatively, the base station may perform aspects of the describedfunctions using special-purpose hardware.

At 3405, the method may include establishing a first link with a firstdevice based on a first random-access procedure, the first linkincluding a control link associated with controlling a state of thefirst device, the first device including a reflective surface forforwarding signals associated with a second link from the base stationto a second device in a wireless network. The operations of 3405 may beperformed in accordance with examples as disclosed herein. In someexamples, aspects of the operations of 3405 may be performed by controllink manager 1815 as described with reference to FIG. 18 .

At 3410, the method may include receiving an uplink transmission fromthe first device to maintain the first link with the base station. Theoperations of 3410 may be performed in accordance with examples asdisclosed herein. In some examples, aspects of the operations of 3410may be performed by control link manager 1815 as described withreference to FIG. 18 .

FIG. 35 shows a flowchart illustrating a method 3500 that supportscontrol link for low-power and simplified transceiver in accordance withaspects of the present disclosure. The operations of the method 3500 maybe implemented by a base station or its components as described herein.For example, the operations of the method 3500 may be performed by abase station 105 as described with reference to FIGS. 1 through 11, 16through 19, and 24 through 27 . In some examples, a base station mayexecute a set of instructions to control the functional elements of thebase station to perform the described functions. Additionally oralternatively, the base station may perform aspects of the describedfunctions using special-purpose hardware.

At 3505, the method may include establishing a first link with a firstdevice based on a first random-access procedure, the first linkincluding a control link associated with controlling a state of thefirst device, the first device including a reflective surface forforwarding signals associated with a second link from the base stationto a second device in a wireless network. The operations of 3505 may beperformed in accordance with examples as disclosed herein. In someexamples, aspects of the operations of 3505 may be performed by controllink manager 1815 as described with reference to FIG. 18 .

At 3510, the method may include receiving a random-access preamble fromthe first device to maintain the first link with the base station, therandom access preamble indicating a first quantity of control commandsreceived from the base station The operations of 3510 may be performedin accordance with examples as disclosed herein. In some examples,aspects of the operations of 3510 may be performed by control linkmanager 1815 as described with reference to FIG. 18 .

FIG. 36 shows a flowchart illustrating a method 3600 that supportscontrol link for low-power and simplified transceiver in accordance withone or more aspects of the present disclosure. The operations of method3600 may be implemented by a UE 115 or its components as describedherein. For example, the operations of method 3600 may be performed by acommunications manager as described with reference to FIGS. 12 through15 . In some examples, a UE may execute a set of instructions to controlthe functional elements of the UE to perform the functions describedbelow. Additionally, or alternatively, a UE may perform aspects of thefunctions described below using special-purpose hardware.

At 3605, the UE may perform a first random-access procedure to establisha control link with a base station, the UE including a reflectivesurface for forwarding signals from the base station to a device in awireless network. The operations of 3605 may be performed according tothe methods described herein. In some examples, aspects of theoperations of 3605 may be performed by a random-access manager asdescribed with reference to FIGS. 12 through 15 .

At 3610, the UE may detect that the control link with the base stationis lost based on a timer or counter expiring or based on failing toreceive signaling from the base station. The operations of 3610 may beperformed according to the methods described herein. In some examples,aspects of the operations of 3610 may be performed by a control linkmanager as described with reference to FIGS. 12 through 15 .

At 3615, the UE may perform a second random-access procedure tore-establish the control link with the base station based on detectingthat the control link with the base station is lost. The operations of3615 may be performed according to the methods described herein. In someexamples, aspects of the operations of 3615 may be performed by arandom-access manager as described with reference to FIGS. 12 through 15.

FIG. 37 shows a flowchart illustrating a method 3700 that supportscontrol link for low-power and simplified transceiver in accordance withone or more aspects of the present disclosure. The operations of method3700 may be implemented by a base station 105 or its components asdescribed herein. For example, the operations of method 3700 may beperformed by a communications manager as described with reference toFIGS. 16 through 19 . In some examples, a base station may execute a setof instructions to control the functional elements of the base stationto perform the functions described below. Additionally, oralternatively, a base station may perform aspects of the functionsdescribed below using special-purpose hardware.

At 3705, the base station may perform a first random-access procedure toestablish a control link with a UE, the UE including a reflectivesurface for forwarding signals from the base station to a device in awireless network. The operations of 3705 may be performed according tothe methods described herein. In some examples, aspects of theoperations of 3705 may be performed by a random-access manager asdescribed with reference to FIGS. 16 through 19 .

At 3710, the base station may transmit signaling to the UE to maintainthe control link with the UE. The operations of 3710 may be performedaccording to the methods described herein. In some examples, aspects ofthe operations of 3710 may be performed by a control link manager asdescribed with reference to FIGS. 16 through 19 .

At 3715, the base station may perform a second random-access procedureto re-establish the control link with the UE after the control link withthe UE is lost. The operations of 3715 may be performed according to themethods described herein. In some examples, aspects of the operations of3715 may be performed by a random-access manager as described withreference to FIGS. 16 through 19 .

FIG. 38 shows a flowchart illustrating a method 3800 that supportscontrol link for low-power and simplified transceiver in accordance withone or more aspects of the present disclosure. The operations of method3800 may be implemented by a UE 115 or its components as describedherein. For example, the operations of method 3800 may be performed by acommunications manager as described with reference to FIGS. 12 through15 . In some examples, a UE may execute a set of instructions to controlthe functional elements of the UE to perform the functions describedbelow. Additionally, or alternatively, a UE may perform aspects of thefunctions described below using special-purpose hardware.

At 3805, the UE may perform a first random-access procedure to establisha control link with a base station, the UE including a reflectivesurface for forwarding signals from the base station to a device in awireless network. The operations of 3805 may be performed according tothe methods described herein. In some examples, aspects of theoperations of 3805 may be performed by a random-access manager asdescribed with reference to FIGS. 12 through 15 .

At 3810, the UE may transmit an uplink transmission to the base stationto maintain the control link with the base station. The operations of3810 may be performed according to the methods described herein. In someexamples, aspects of the operations of 3810 may be performed by acontrol link manager as described with reference to FIGS. 12 through 15.

FIG. 39 shows a flowchart illustrating a method 3900 that supportscontrol link for low-power and simplified transceiver in accordance withone or more aspects of the present disclosure. The operations of method3900 may be implemented by a base station 105 or its components asdescribed herein. For example, the operations of method 3900 may beperformed by a communications manager as described with reference toFIGS. 16 through 19 . In some examples, a base station may execute a setof instructions to control the functional elements of the base stationto perform the functions described below. Additionally, oralternatively, a base station may perform aspects of the functionsdescribed below using special-purpose hardware.

At 3905, the base station may perform a first random-access procedure toestablish a control link with a UE, the UE including a reflectivesurface for forwarding signals from the base station to a device in awireless network. The operations of 3905 may be performed according tothe methods described herein. In some examples, aspects of theoperations of 3905 may be performed by a random-access manager asdescribed with reference to FIGS. 16 through 19 .

At 3910, the base station may receive an uplink transmission from the UEto maintain the control link with the base station. The operations of3910 may be performed according to the methods described herein. In someexamples, aspects of the operations of 3910 may be performed by acontrol link manager as described with reference to FIGS. 16 through 19.

FIG. 40 shows a flowchart illustrating a method 4000 that supportsrandom-access procedure for low-power and simplified transceiver inaccordance with one or more aspects of the present disclosure. Theoperations of method 4000 may be implemented by a UE 115 or itscomponents as described herein. For example, the operations of method4000 may be performed by a communications manager as described withreference to FIGS. 20 through 23 . In some examples, a UE may execute aset of instructions to control the functional elements of the UE toperform the functions described below. Additionally, or alternatively, aUE may perform aspects of the functions described below usingspecial-purpose hardware.

At 4005, the UE may initiate a random-access procedure to connect to abase station. The operations of 4005 may be performed according to themethods described herein. In some examples, aspects of the operations of4005 may be performed by a random-access manager as described withreference to FIGS. 20 through 23 .

At 4010, the UE may transmit, to the base station, an indication thatthe UE includes a reflective surface for forwarding signals from thebase station to a device in a wireless network. The operations of 4010may be performed according to the methods described herein. In someexamples, aspects of the operations of 4010 may be performed by acapability manager as described with reference to FIGS. 20 through 23 .

At 4015, the UE may receive signals from the base station for forwardingto the device in the wireless network based on transmitting theindication. The operations of 4015 may be performed according to themethods described herein. In some examples, aspects of the operations of4015 may be performed by a forwarding manager as described withreference to FIGS. 20 through 23 .

FIG. 41 shows a flowchart illustrating a method 4100 that supportsrandom-access procedure for low-power and simplified transceiver inaccordance with one or more aspects of the present disclosure. Theoperations of method 4100 may be implemented by a base station 105 orits components as described herein. For example, the operations ofmethod 4100 may be performed by a communications manager as describedwith reference to FIGS. 24 through 27 . In some examples, a base stationmay execute a set of instructions to control the functional elements ofthe base station to perform the functions described below. Additionally,or alternatively, a base station may perform aspects of the functionsdescribed below using special-purpose hardware.

At 4105, the base station may receive, from a UE, an indication that theUE includes a reflective surface for forwarding signals from the basestation to a device in a wireless network. The operations of 4105 may beperformed according to the methods described herein. In some examples,aspects of the operations of 4105 may be performed by a capabilitymanager as described with reference to FIGS. 24 through 27 .

At 4110, the base station may transmit signals to the UE for forwardingto the device in the wireless network based on receiving the indication.The operations of 4110 may be performed according to the methodsdescribed herein. In some examples, aspects of the operations of 4110may be performed by a forwarding manager as described with reference toFIGS. 24 through 27 .

The following provides an overview of aspects of the present disclosure:

Aspect 1: A method for wireless communication at a first device,comprising: establishing a first link with the base station based atleast in part on a first random access procedure, the first linkcomprising a control link associated with controlling a state of thefirst device, the first device comprising a reflective surface forforwarding signals associated with a second link from the base stationto a second device in a wireless network; detecting that the first linkwith the base station is lost based at least in part on a timer orcounter expiring or based at least in part on failing to receivesignaling from the base station; and re-establishing the first link withthe base station based at least in part on detecting that the first linkwith the base station is lost, the first link re-established based on asecond random access procedure.

Aspect 2: The method of aspect 1, further comprising: failing to receiveone or more periodic indicators in a control channel, wherein detectingthat the first link with the base station is lost is based at least inpart on failing to receive the one or more periodic indicators in thecontrol channel.

Aspect 3: The method of aspect 2, further comprising: incrementing acounter after failing to receive each of the one or more periodicindicators in the control channel, wherein detecting that the first linkwith the base station is lost is based at least in part on the counterexceeding a threshold.

Aspect 4: The method of aspect 2, further comprising: decrementing acounter after failing to receive each of the one or more periodicindicators in the control channel, wherein detecting that the first linkwith the base station is lost is based at least in part on the counterreaching zero.

Aspect 5: The method of any of aspects 1 through 4, further comprising:identifying that the first link with the base station is valid for aduration of the timer, wherein detecting that the first link with thebase station is lost is based at least in part on the timer expiring.

Aspect 6: The method of any of aspects 1 through 5, further comprising:failing to detect energy from the base station for a duration of thetimer, wherein detecting that the first link with the base station islost is based at least in part on failing to detect the energy from thebase station for the duration of the timer.

Aspect 7: The method of aspect 6, further comprising: restarting thetimer after detecting energy from the base station.

Aspect 8: The method of any of aspects 1 through 7, wherein performingthe second random-access procedure comprises: performing acontention-free random-access procedure using a cell radio networktemporary identifier (C-RNTI) to re-establish the first link with thebase station.

Aspect 9: The method of any of aspects 1 through 8, further comprising:transmitting, to the base station, a random-access preamble comprisingan indication that the first device comprises the reflective surface,the random-access preamble initiating the first random-access procedurewith the base station.

Aspect 10: The method of aspect 9, further comprising: identifying therandom-access preamble from one or more random-access preambles reservedfor indicating that the first device comprises the reflective surface.

Aspect 11: The method of any of aspects 1 through 10, wherein the firstdevice comprises a UE; and the second device comprises a UE; or thesecond device comprises a base station.

Aspect 12: A method for wireless communication at a base station,comprising: establishing a first link with a first device based at leastin part on a first random-access procedure, the first link comprising acontrol link associated with controlling a state of the first device,the first device comprising a reflective surface for forwarding signalsassociated with a second link from the base station to a second devicein a wireless network transmitting signaling to the first device tomaintain the first link with the first device; and performing a secondrandom-access procedure to re-establish the first link with the firstdevice after the first link with the first device is lost.

Aspect 13: The method of aspect 12, wherein transmitting signaling tothe first device to maintain the first link with the first devicecomprises: transmitting one or more periodic indicators in a controlchannel to the base station, wherein the first link with the firstdevice is lost when the first device fails to receive a threshold numberof the one or more periodic indicators.

Aspect 14: The method of any of aspects 12 through 13, furthercomprising: receiving, from a first device, a random-access preamblecomprising an indication that the first device comprises the reflectivesurface, the random-access preamble initiating the first random-accessprocedure with the first device.

Aspect 15: The method of any of aspects 12 through 14, whereinperforming the second random-access procedure comprises: performing acontention-free random-access procedure using a cell radio networktemporary identifier (C-RNTI) to re-establish the first link with theUE.

Aspect 16: A method for wireless communication at a first device,comprising: establishing a first link with a base station based at leastin part on a first random-access procedure, the first link comprising acontrol link associated with controlling a state of the first device,the first device comprising a reflective surface for forwarding signalsassociated with a second link from the base station to a second devicein a wireless network; and transmitting an uplink transmission to thebase station to maintain the first link with the base station.

Aspect 17: The method of aspect 16, wherein the uplink transmissioncomprises a scheduling request.

Aspect 18: The method of any of aspects 16 through 17, wherein theuplink transmission comprises a periodic uplink transmission.

Aspect 19: The method of any of aspects 16 through 18, furthercomprising: receiving a request for the uplink transmission from thebase device in response to a downlink transmission; and receiving thedownlink transmission from the base station, wherein the uplinktransmission is received in response to the downlink transmission.

Aspect 20: The method of any of aspects 16 through 19, whereintransmitting the uplink transmission to the base station comprises:transmitting a random-access preamble indicating a quantity of controlcommands received from the base station.

Aspect 21: The method of any of aspects 16 through 20, furthercomprising: transmitting, to the base station, a random-access preamblecomprising an indication that the first device comprises a reflectivesurface, the random-access preamble initiating the first random-accessprocedure with the base station.

Aspect 22: The method of aspect 21, further comprising: identifying therandom-access preamble from one or more random-access preambles reservedfor indicating that the first device comprises the reflective surface.

Aspect 23: The method of any of aspects 16 through 22, wherein the firstdevice comprises a UE; and the second device comprises a UE; or thesecond device comprises a base station.

Aspect 24: A method for wireless communication at a base station,comprising: establishing a first link with a first device based at leastin part on a first random-access procedure, the first link comprising acontrol link associated with controlling a state of the first device,the first device comprising a reflective surface for forwarding signalsassociated with a second link from the base station to a second devicein a wireless network; and receiving an uplink transmission from thefirst device to maintain the first link with the base station.

Aspect 25: The method of aspect 24, further comprising: failing toreceive one or more uplink transmissions from the first device;detecting that the first link with the first device is lost based atleast in part on failing to receive the one or more uplink transmissionsfrom the first device; and avoiding transmitting downlink signals to thefirst device for forwarding to the device in the wireless network untilthe first device performs a second random-access procedure tore-establish the first link with the base station.

Aspect 26: The method of any of aspects 24 through 25, wherein theuplink transmission comprises a scheduling request.

Aspect 27: The method of any of aspects 24 through 26, wherein theuplink transmission comprises a periodic uplink transmission.

Aspect 28: The method of any of aspects 24 through 27, furthercomprising: transmitting a request for the uplink transmission from thefirst device in response to a downlink transmission; and transmittingthe downlink transmission to the first device, wherein the uplinktransmission is received in response to the downlink transmission.

Aspect 29: The method of any of aspects 24 through 28, wherein receivingthe uplink transmission from the first device comprises: receiving arandom-access preamble indicating a first quantity of control commandsreceived from the base station.

Aspect 30: The method of aspect 29, further comprising: determining thata second quantity of control commands transmitted by the base stationexceeds the first quantity of control commands received by the firstdevice by a threshold amount; detecting that the first link with thefirst device is lost based at least in part on the determining; andavoiding transmitting downlink signals to the first device forforwarding to the device in the wireless network until the first deviceperforms a second random-access procedure to re-establish the first linkwith the base station.

Aspect 31: An apparatus for wireless communication comprising aprocessor and memory coupled to the processor. The processor and memorymay be configured to cause the apparatus to perform a method of any ofaspects 1 through 11.

Aspect 32: An apparatus for wireless communication at a first device,comprising at least one means for performing a method of any of aspects1 through 11.

Aspect 33: A non-transitory computer-readable medium storing code forwireless communication at a first device, the code comprisinginstructions executable by a processor to perform a method of any ofaspects 1 through 11.

Aspect 34: An apparatus for wireless communication comprising aprocessor and memory coupled to the processor. The processor and memorymay be configured to cause the apparatus to perform a method of any ofaspects 12 through 15.

Aspect 35: An apparatus for wireless communication at a base station,comprising at least one means for performing a method of any of aspects12 through 15.

Aspect 36: A non-transitory computer-readable medium storing code forwireless communication at a base station, the code comprisinginstructions executable by a processor to perform a method of any ofaspects 12 through 15.

Aspect 37: An apparatus for wireless communication comprising aprocessor and memory coupled to the processor. The processor and memorymay be configured to cause the apparatus to perform a method of any ofaspects 16 through 23.

Aspect 38: An apparatus for wireless communication at a first device,comprising at least one means for performing a method of any of aspects16 through 23.

Aspect 39: A non-transitory computer-readable medium storing code forwireless communication at a first device, the code comprisinginstructions executable by a processor to perform a method of any ofaspects 16 through 23.

Aspect 40: An apparatus for wireless communication comprising aprocessor and memory coupled to the processor. The processor and memorymay be configured to cause the apparatus to perform a method of any ofaspects 24 through 30.

Aspect 41: An apparatus for wireless communication at a base station,comprising at least one means for performing a method of any of aspects24 through 30.

Aspect 42: A non-transitory computer-readable medium storing code forwireless communication at a base station, the code comprisinginstructions executable by a processor to perform a method of any ofaspects 24 through 30.

Aspect 43: A method for wireless communications at a UE, comprising:performing a first random-access procedure to establish a control linkwith a base station, the UE comprising a reflective surface forforwarding signals from the base station to a device in a wirelessnetwork, detecting that the control link with the base station is lostbased at least in part on a timer or counter expiring or based at leastin part on failing to receive signaling from the base station, andperforming a second random-access procedure to re-establish the controllink with the base station based at least in part on detecting that thecontrol link with the base station is lost.

Aspect 44: The method of aspect 1, further comprising: failing toreceive one or more periodic indicators in a control channel, whereindetecting that the control link with the base station is lost is basedat least in part on failing to receive the one or more periodicindicators in the control channel.

Aspect 45: The method of any one of aspects 1 or 2, further comprising:incrementing a counter after failing to receive each of the one or moreperiodic indicators in the control channel, wherein detecting that thecontrol link with the base station is lost is based at least in part onthe counter exceeding a threshold.

Aspect 46: The method of any one of aspects 1 through 3, furthercomprising: decrementing a counter after failing to receive each of theone or more periodic indicators in the control channel, whereindetecting that the control link with the base station is lost is basedat least in part on the counter reaching zero.

Aspect 47: The method of any one of aspects 1 through 4, furthercomprising: identifying that the control link with the base station isvalid for a duration of the timer, wherein detecting that the controllink with the base station is lost is based at least in part on thetimer expiring.

Aspect 48: The method of any one of aspects 1 through 5, furthercomprising: failing to detect energy from the base station for aduration of the timer, wherein detecting that the control link with thebase station is lost is based at least in part on failing to detect theenergy from the base station for the duration of the timer.

Aspect 49: The method of any one of aspects 1 through 6, furthercomprising: restarting the timer after detecting energy from the basestation.

Aspect 50: The method of any one of aspects 1 through 7, whereinperforming the second random-access procedure comprises: performing acontention-free random-access procedure using a C-RNTI to re-establishthe control link with the base station.

Aspect 51: A method for wireless communications at a base station,comprising: performing a first random-access procedure to establish acontrol link with a user equipment (UE), the UE comprising a reflectivesurface for forwarding signals from the base station to a device in awireless network, transmitting signaling to the UE to maintain thecontrol link with the UE, and performing a second random-accessprocedure to re-establish the control link with the UE after the controllink with the UE is lost.

Aspect 52: The method of aspect 9, wherein transmitting signaling to theUE to maintain the control link with the UE comprises: transmitting oneor more periodic indicators in a control channel to the base station,wherein the control link with the UE is lost when the UE fails toreceive a threshold number of the one or more periodic indicators.

Aspect 53: The method of any one of aspects 9 or 10, wherein performingthe second random-access procedure comprises: performing acontention-free random-access procedure using a C-RNTI to re-establishthe control link with the UE.

Aspect 54: A method for wireless communications at a UE, comprising:performing a first random-access procedure to establish a control linkwith a base station, the UE comprising a reflective surface forforwarding signals from the base station to a device in a wirelessnetwork, and transmitting an uplink transmission to the base station tomaintain the control link with the base station.

Aspect 55: The method of aspect 12, wherein the uplink transmissioncomprises a scheduling request.

Aspect 56: The method of any one of aspects 12 or 13, wherein the uplinktransmission comprises a periodic uplink transmission.

Aspect 57: The method of any one of aspects 12 through 14, furthercomprising: receiving a request for the uplink transmission from the UEin response to a downlink transmission, and receiving the downlinktransmission from the base station, wherein the uplink transmission isreceived in response to the downlink transmission.

Aspect 58: The method of any one of aspects 12 through 15, whereintransmitting the uplink transmission to the base station comprises:transmitting a random-access preamble indicating a quantity of controlcommands received from the base station.

Aspect 59: A method for wireless communications at a base station,comprising: performing a first random-access procedure to establish acontrol link with a UE, the UE comprising a reflective surface forforwarding signals from the base station to a device in a wirelessnetwork, and receiving an uplink transmission from the UE to maintainthe control link with the base station.

Aspect 60: The method of aspect 17, further comprising: failing toreceive one or more uplink transmissions from the UE, detecting that thecontrol link with the UE is lost based at least in part on failing toreceive the one or more uplink transmissions from the UE, and avoidingtransmitting downlink signals to the UE for forwarding to the device inthe wireless network until the UE performs a second random-accessprocedure to re-establish the control link with the base station.

Aspect 61: The method of any one of aspects 17 or 18, wherein the uplinktransmission comprises a scheduling request.

Aspect 62: The method of any one of aspects 17 through 19, wherein theuplink transmission comprises a periodic uplink transmission.

Aspect 63: The method of any one of aspects 17 through 20, furthercomprising: transmitting a request for the uplink transmission from theUE in response to a downlink transmission, and transmitting the downlinktransmission to the UE, wherein the uplink transmission is received inresponse to the downlink transmission.

Aspect 64: The method of any one of aspects 17 through 21, whereinreceiving the uplink transmission from the UE comprises: receiving arandom-access preamble indicating a first quantity of control commandsreceived from the base station.

Aspect 65: The method of any one of aspects 17 through 22, furthercomprising: determining that a second quantity of control commandstransmitted by the base station exceeds the first quantity of controlcommands received by the UE by a threshold amount, detecting that thecontrol link with the UE is lost based at least in part on thedetermining, and avoiding transmitting downlink signals to the UE forforwarding to the device in the wireless network until the UE performs asecond random-access procedure to re-establish the control link with thebase station.

Aspect 66: An apparatus for wireless communication comprising at leastone means for performing a method of any one of aspects 43 through 50.

Aspect 67: An apparatus for wireless communication comprising aprocessor and memory coupled to the processor. The processor and memorymay be configured to cause the apparatus to perform a method of any oneof aspects 43 through 50.

Aspect 68: A non-transitory computer-readable medium storing code forwireless communication comprising a processor, memory coupled to theprocessor, and instructions stored in the memory and executable by theprocessor to cause the apparatus to perform a method of any one ofaspects 43 through 50.

Aspect 69: An apparatus for wireless communication comprising at leastone means for performing a method of any one of aspects 51 through 53.

Aspect 70: An apparatus for wireless communication comprising aprocessor and memory coupled to the processor. The processor and memorymay be configured to cause the apparatus to perform a method of any oneof aspects 51 through 53.

Aspect 71: A non-transitory computer-readable medium storing code forwireless communication comprising a processor, memory coupled to theprocessor, and instructions stored in the memory and executable by theprocessor to cause the apparatus to perform a method of any one ofaspects 51 through 53.

Aspect 72: An apparatus for wireless communication comprising at leastone means for performing a method of any one of aspects 54 through 58.

Aspect 73: An apparatus for wireless communication comprising aprocessor and memory coupled to the processor. The processor and memorymay be configured to cause the apparatus to perform a method of any oneof aspects 54 through 58.

Aspect 74: A non-transitory computer-readable medium storing code forwireless communication comprising a processor, memory coupled to theprocessor, and instructions stored in the memory and executable by theprocessor to cause the apparatus to perform a method of any one ofaspects 54 through 58.

Aspect 75: An apparatus for wireless communication comprising at leastone means for performing a method of any one of aspects 59 through 65.

Aspect 76: An apparatus for wireless communication comprising aprocessor and memory coupled to the processor. The processor and memorymay be configured to cause the apparatus to perform a method of any oneof aspects 59 through 65.

Aspect 77: A non-transitory computer-readable medium storing code forwireless communication comprising a processor, memory coupled to theprocessor, and instructions stored in the memory and executable by theprocessor to cause the apparatus to perform a method of any one ofaspects 59 through 65.

Aspect 78: A method for wireless communications at a UE, comprising:initiating a random-access procedure to connect to a base station,transmitting, to the base station, an indication that the UE comprises areflective surface for forwarding signals from the base station to adevice in a wireless network, and receiving signals from the basestation for forwarding to the device in the wireless network based atleast in part on transmitting the indication.

Aspect 79: The method of aspect 78, wherein transmitting the indicationthat the UE comprises the reflective surface comprises: transmitting arandom-access preamble indicating that the UE comprises the reflectivesurface.

Aspect 80: The method of any one of aspects 78 or 79, furthercomprising: identifying the random-access preamble from one or morerandom-access preambles reserved for indicating that the UE comprisesthe reflective surface.

Aspect 81: The method of any one of aspects 78 through 80, whereintransmitting the indication that the UE comprises the reflective surfacecomprises: transmitting a first random-access message in a two-steprandom-access procedure comprising the indication that the UE comprisesthe reflective surface.

Aspect 82: The method of any one of aspects 78 through 81, whereintransmitting the indication that the UE comprises the reflective surfacecomprises: transmitting a third random-access message in a four-steprandom-access procedure comprising the indication that the UE comprisesthe reflective surface.

Aspect 83: The method of any one of aspects 78 through 82, whereintransmitting the indication that the UE comprises the reflective surfacecomprises: transmitting, after the random-access procedure, an RRCmessage indicating that the UE comprises the reflective surface.

Aspect 84: The method of any one of aspects 78 through 83, furthercomprising: receiving an indication of one or more random-accesspreambles reserved for indicating that the UE comprises the reflectivesurface, and transmitting, as part of a subsequent random-accessprocedure, a random-access preamble of the one or more random-accesspreambles indicating that the UE comprises the reflective surface.

Aspect 85: The method of any one of aspects 78 through 84, furthercomprising receiving, from the base station, a command indicating asweep pattern, sweep direction, center frequency, bandwidth, or acombination thereof for forwarding signals from the base station to thedevice in the wireless network, and forwarding signals from the basestation to the device in the wireless network based at least in part onreceiving the command.

Aspect 86: The method of any one of aspects 78 through 85, furthercomprising: receiving, from the base station, a command indicatingpositive or negative feedback for signals forwarded from the basestation to the device in the wireless network, tuning parameters forforwarding signals from the base station to the device in the wirelessnetwork based at least in part on the command, and forwarding signalsfrom the base station to the device in the wireless network based atleast in part on the tuning.

Aspect 87: The method of any one of aspects 78 through 86, furthercomprising: transmitting an indication of a location of the device inthe wireless network to the base station.

Aspect 88: The method of any one of aspects 78 through 87, furthercomprising: receiving one or more signals from the base station, andreflecting the one or more signals back to the base station at a sameangle at which the one or more signals are received.

Aspect 89: The method of any one of aspects 78 through 88, wherein theUE comprises a low-power UE and the reflective surface comprises an IRS.

Aspect 90: A method for wireless communications at a base station,comprising: receiving, from a UE, an indication that the UE comprises areflective surface for forwarding signals from the base station to adevice in a wireless network, and transmitting signals to the UE forforwarding to the device in the wireless network based at least in parton receiving the indication.

Aspect 91: The method of aspect 90, wherein receiving the indicationthat the UE comprises the reflective surface comprises: receiving arandom-access preamble indicating that the UE comprises the reflectivesurface.

Aspect 92: The method of any one of aspects 90 or 91, wherein receivingthe indication that the UE comprises the reflective surface comprises:receiving a first random-access message in a two-step random-accessprocedure comprising the indication that the UE comprises the reflectivesurface.

Aspect 93: The method of any one of aspects 90 through 92, whereinreceiving the indication that the UE comprises the reflective surfacecomprises: receiving a third random-access message in a four-steprandom-access procedure comprising the indication that the UE comprisesthe reflective surface.

Aspect 94: The method of any one of aspects 90 through 93, whereinreceiving the indication that the UE comprises the reflective surfacecomprises: receiving, after a random-access procedure, an RRC messageindicating that the UE comprises the reflective surface.

Aspect 95: The method of any one of aspects 90 through 94, furthercomprising: transmitting, to the UE, an indication of one or morerandom-access preambles reserved for indicating that the UE comprisesthe reflective surface and receiving, from the UE as part of asubsequent random-access procedure, a random-access preamble of the oneor more random-access preambles indicating that the UE comprises thereflective surface.

Aspect 96: The method of any one of aspects 90 through 95, furthercomprising: transmitting, to the UE, a command indicating a sweeppattern, sweep direction, center frequency, bandwidth, or a combinationthereof for forwarding signals from the base station to the device inthe wireless network.

Aspect 97: The method of any one of aspects 90 through 96, furthercomprising: receiving, from the device in the wireless network, feedbackon signals forwarded by the UE from the base station to the device inthe wireless network, wherein transmitting the command is based at leastin part on the received feedback.

Aspect 98: The method of any one of aspects 90 through 97, furthercomprising: receiving, from the device in the wireless network, feedbackon signals forwarded by the UE from the base station to the device inthe wireless network and transmitting, to the UE, a command indicatingpositive or negative feedback for signals forwarded from the basestation to the device in the wireless network based at least in part onreceiving the feedback.

Aspect 99: The method of any one of aspect 90 through 98, furthercomprising: transmitting, to the UE on a plurality of beams, a pluralityof signals for forwarding to the device in the wireless network,receiving, from the device in the wireless network, feedback on theplurality of signals forwarded by the UE from the base station to thedevice in the wireless network, identifying a beam of the plurality ofbeams associated with a highest quality based at least in part on thereceived feedback, and selecting the identified beam for transmittingsignals to the UE for forwarding to the device in the wireless network.

Aspect 100: The method of any one of aspects 90 through 99, furthercomprising: receiving an indication of a location of the UE andselecting a beam for transmitting signals to the UE for forwarding tothe device in the wireless network based at least in part on thelocation of the UE.

Aspect 101: The method of any one of aspects 90 through 100, furthercomprising: transmitting a plurality of signals to the UE on a pluralityof beams, receiving a reflection of the plurality of signals from the UEat a same angle at which the plurality of signals are transmitted to theUE on the plurality of beams, identifying a beam of the plurality ofbeams associated with a highest quality based at least in part onreceiving the reflection, and selecting the identified beam fortransmitting signals to the UE for forwarding to the device in thewireless network.

Aspect 102: The method of any one of aspects 90 through 101, furthercomprising: selecting a beam identified in the random-access procedurefor transmitting signals to the UE for forwarding to the device in thewireless network.

Aspect 103: The method of any one of aspects 90 through 102, wherein theUE comprises a low-power UE and the reflective surface comprises an IRS.

Aspect 104: An apparatus for wireless communication comprising at leastone means for performing a method of any one of aspects 78 through 89.

Aspect 105: An apparatus for wireless communication comprising aprocessor and memory coupled to the processor. The processor and memorymay be configured to cause the apparatus to perform a method of any oneof aspects 78 through 89.

Aspect 106: A non-transitory computer-readable medium storing code forwireless communication comprising a processor, memory coupled to theprocessor, and instructions stored in the memory and executable by theprocessor to cause the apparatus to perform a method of any one ofaspects 78 through 89.

Aspect 107: An apparatus for wireless communication comprising at leastone means for performing a method of any one of aspects 90 through 103.

Aspect 108: An apparatus for wireless communication comprising aprocessor and memory coupled to the processor. The processor and memorymay be configured to cause the apparatus to perform a method of any oneof aspects 90 through 103.

Aspect 109: A non-transitory computer-readable medium storing code forwireless communication comprising a processor, memory coupled to theprocessor, and instructions stored in the memory and executable by theprocessor to cause the apparatus to perform a method of any one ofaspects 90 through 103.

It should be noted that the methods described herein describe possibleimplementations, and that the operations and the steps may be rearrangedor otherwise modified and that other implementations are possible.Further, aspects from two or more of the methods may be combined.

Although aspects of an LTE, LTE-A, LTE-A Pro, or NR system may bedescribed for purposes of example, and LTE, LTE-A, LTE-A Pro, or NRterminology may be used in much of the description, the techniquesdescribed herein are applicable beyond LTE, LTE-A, LTE-A Pro, or NRnetworks. For example, the described techniques may be applicable tovarious other wireless communications systems such as Ultra MobileBroadband (UMB), Institute of Electrical and Electronics Engineers(IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, aswell as other systems and radio technologies not explicitly mentionedherein.

Information and signals described herein may be represented using any ofa variety of different technologies and techniques. For example, data,instructions, commands, information, signals, bits, symbols, and chipsthat may be referenced throughout the description may be represented byvoltages, currents, electromagnetic waves, magnetic fields or particles,optical fields or particles, or any combination thereof.

The various illustrative blocks and components described in connectionwith the disclosure herein may be implemented or performed with ageneral-purpose processor, a DSP, an ASIC, a CPU, an FPGA or otherprogrammable logic device, discrete gate or transistor logic, discretehardware components, or any combination thereof designed to perform thefunctions described herein. A general-purpose processor may be amicroprocessor, but in the alternative, the processor may be anyprocessor, controller, microcontroller, or state machine. A processormay also be implemented as a combination of computing devices (e.g., acombination of a DSP and a microprocessor, multiple microprocessors, oneor more microprocessors in conjunction with a DSP core, or any othersuch configuration).

The functions described herein may be implemented in hardware, softwareexecuted by a processor, firmware, or any combination thereof. Ifimplemented in software executed by a processor, the functions may bestored on or transmitted over as one or more instructions or code on acomputer-readable medium. Other examples and implementations are withinthe scope of the disclosure and appended claims. For example, due to thenature of software, functions described herein may be implemented usingsoftware executed by a processor, hardware, firmware, hardwiring, orcombinations of any of these. Features implementing functions may alsobe physically located at various positions, including being distributedsuch that portions of functions are implemented at different physicallocations.

Computer-readable media includes both non-transitory computer storagemedia and communication media including any medium that facilitatestransfer of a computer program from one place to another. Anon-transitory storage medium may be any available medium that may beaccessed by a general-purpose or special purpose computer. By way ofexample, and not limitation, non-transitory computer-readable media mayinclude RAM, ROM, electrically erasable programmable ROM (EEPROM), flashmemory, compact disk (CD) ROM or other optical disk storage, magneticdisk storage or other magnetic storage devices, or any othernon-transitory medium that may be used to carry or store desired programcode means in the form of instructions or data structures and that maybe accessed by a general-purpose or special-purpose computer, or ageneral-purpose or special-purpose processor. Also, any connection isproperly termed a computer-readable medium. For example, if the softwareis transmitted from a website, server, or other remote source using acoaxial cable, fiber optic cable, twisted pair, digital subscriber line(DSL), or wireless technologies such as infrared, radio, and microwave,then the coaxial cable, fiber optic cable, twisted pair, DSL, orwireless technologies such as infrared, radio, and microwave areincluded in the definition of computer-readable medium. Disk and disc,as used herein, include CD, laser disc, optical disc, digital versatiledisc (DVD), floppy disk and Blu-ray disc where disks usually reproducedata magnetically, while discs reproduce data optically with lasers.Combinations of the above are also included within the scope ofcomputer-readable media.

As used herein, including in the claims, “or” as used in a list of items(e.g., a list of items prefaced by a phrase such as “at least one of” or“one or more of”) indicates an inclusive list such that, for example, alist of at least one of A, B, or C means A or B or C or AB or AC or BCor ABC (i.e., A and B and C). Also, as used herein, the phrase “basedon” shall not be construed as a reference to a closed set of conditions.For example, an example step that is described as “based on condition A”may be based on both a condition A and a condition B without departingfrom the scope of the present disclosure. In other words, as usedherein, the phrase “based on” shall be construed in the same manner asthe phrase “based at least in part on.”

In the appended figures, similar components or features may have thesame reference label. Further, various components of the same type maybe distinguished by following the reference label by a dash and a secondlabel that distinguishes among the similar components. If just the firstreference label is used in the specification, the description isapplicable to any one of the similar components having the same firstreference label irrespective of the second reference label, or othersubsequent reference label.

The description set forth herein, in connection with the appendeddrawings, describes example configurations and does not represent allthe examples that may be implemented or that are within the scope of theclaims. The term “example” used herein means “serving as an example,instance, or illustration,” and not “preferred” or “advantageous overother examples.” The detailed description includes specific details forthe purpose of providing an understanding of the described techniques.These techniques, however, may be practiced without these specificdetails. In some instances, known structures and devices are shown inblock diagram form in order to avoid obscuring the concepts of thedescribed examples.

The description herein is provided to enable a person having ordinaryskill in the art to make or use the disclosure. Various modifications tothe disclosure will be apparent to a person having ordinary skill in theart, and the generic principles defined herein may be applied to othervariations without departing from the scope of the disclosure. Thus, thedisclosure is not limited to the examples and designs described herein,but is to be accorded the broadest scope consistent with the principlesand novel features disclosed herein.

What is claimed is:
 1. An apparatus for wireless communication at afirst device, comprising: one or more memories; and one or moreprocessors coupled with the one or more memories and configured to causethe first device to: establish a first link with a network entity via afirst random-access procedure, the first link comprising a control linkto control a state of the first device, wherein a control signal tocontrol the state of the first device is embedded in one or morerandom-access messages of the random-access procedure, the controlsignal associated with the control link; detect that the first link withthe network entity is lost based at least in part on expiry of a timeror a counter or based at least in part on a failure to receive signalingfrom the network entity; and re-establish the first link with thenetwork entity based at least in part on the detection that the firstlink with the network entity is lost, the first link re-establishedbased on a second random-access procedure.
 2. The apparatus of claim 1,wherein, to establish the first link, the one or more processors arefurther configured to cause the first device to: exchange random-accessmessages with the network entity to establish the first link; andrefrain from an exchange of radio resource control (RRC) signaling withthe network entity after the first link is established.
 3. The apparatusof claim 1, the first device comprising a reflective surface to forwardsignals associated with a second link from the network entity to asecond device in a wireless network.
 4. The apparatus of claim 3,wherein the one or more processors are configured to cause the firstdevice to: receive, from the network entity via the first link, amessage that indicates a configuration for the reflective surface,control of the state of the first device comprising control of thereflective surface via the configuration.
 5. The apparatus of claim 1,wherein the one or more processors are configured to cause the firstdevice to: fail to receive one or more periodic indicators in a controlchannel, wherein the detection that the first link with the networkentity is lost is based at least in part on the failure to receive theone or more periodic indicators in the control channel.
 6. The apparatusof claim 5, wherein the one or more processors are configured to causethe first device to: increment the counter after the failure to receiveeach of the one or more periodic indicators in the control channel,wherein the detection that the first link with the network entity islost is based at least in part on exceedance of a threshold by thecounter.
 7. The apparatus of claim 5, wherein the one or more processorsare configured to cause the first device to: decrement the counter afterthe failure to receive each of the one or more periodic indicators inthe control channel, wherein the detection that the first link with thenetwork entity is lost is based at least in part on arrival of thecounter at a zero value.
 8. The apparatus of claim 1, wherein the one ormore processors are configured to cause the first device to: determinethat the first link with the network entity is valid for a duration ofthe timer, wherein the detection that the first link with the networkentity is lost is based at least in part on expiry of the timer.
 9. Theapparatus of claim 1, wherein the one or more processors are configuredto cause the first device to: fail to detect energy from the networkentity for a duration of the timer, wherein the detection that the firstlink with the network entity is lost is based at least in part on thefailure to detect the energy from the network entity for the duration ofthe timer.
 10. The apparatus of claim 9, wherein the one or moreprocessors are configured to cause the first device to: restart thetimer after the detection of the energy from the network entity.
 11. Theapparatus of claim 1, wherein, to perform the second random-accessprocedure, the one or more processors are configured to cause the firstdevice to: perform a contention-free random-access procedure based atleast in part on use of a cell radio network temporary identifier(C-RNTI) to re-establish the first link with the network entity.
 12. Theapparatus of claim 1, wherein the one or more processors are configuredto cause the first device to: transmit, to the network entity, arandom-access preamble comprising an indication that the first devicecomprises a reflective surface, wherein the random-access preambleinitiates the first random-access procedure with the network entity. 13.The apparatus of claim 12, wherein the one or more processors areconfigured to cause the first device to: select the random-accesspreamble from one or more random-access preambles reserved forindication that the first device comprises the reflective surface. 14.The apparatus of claim 1, wherein: the first device comprises a firstuser equipment (UE); and the second device comprises one of a second UEor a second network entity.
 15. An apparatus for wireless communicationat a network entity, comprising: one or more memories; and one or moreprocessors coupled with the one or more memories and configured to causethe network entity to: establish a first link with a first device via afirst random-access procedure, the first link comprising a control linkto control a state of the first device; output, to the first device viathe first link, a message that indicates a configuration for areflective surface; output signaling to the first device to maintain thefirst link with the first device; and perform a second random-accessprocedure to re-establish the first link with the first device after thefirst link with the first device is lost.
 16. The apparatus of claim 15,wherein, to establish the first link, the one or more processors areconfigured to cause the network entity to: exchange random-accessmessages with the first device to establish the first link; and refrainfrom an exchange of radio resource control (RRC) signaling with thefirst device after the first link is established.
 17. The apparatus ofclaim 15, the first device comprising the reflective surface to forwardsignals associated with a second link from the network entity to asecond device in a wireless network.
 18. The apparatus of claim 15,wherein the message that indicates the configuration for the reflectivesurface comprising a control signal to control the state of the firstdevice, the control signal embedded in one or more random-accessmessages of the random-access procedure.
 19. The apparatus of claim 15,wherein, to output signaling to the first device to maintain the firstlink with the first device, the one or more processors are configured tocause the network entity to: output one or more periodic indicators in acontrol channel to the first device, wherein the first link with thefirst device is lost when the first device fails to receive a thresholdnumber of the one or more periodic indicators.
 20. The apparatus ofclaim 15, wherein the one or more processors are configured to cause thenetwork entity to: obtain, from the first device, a random-accesspreamble comprising an indication that the first device comprises thereflective surface, wherein the random-access preamble initiates thefirst random-access procedure with the first device.
 21. The apparatusof claim 15, wherein, to perform the second random-access procedure, theone or more processors are configured to cause the network entity to:perform a contention-free random-access procedure based at least in parton use of a cell radio network temporary identifier (C-RNTI) tore-establish the first link with the first device.
 22. A method forwireless communication at a first device, comprising: establishing afirst link with a network entity via a first random-access procedure,the first link comprising a control link to control a state of the firstdevice, wherein a control signal to control the state of the firstdevice is embedded in one or more random-access messages of therandom-access procedure, the control signal associated with the controllink; detecting that the first link with the network entity is lostbased at least in part on a timer or a counter expiring or based atleast in part on failing to receive signaling from the network entity;and re-establishing the first link with the network entity based atleast in part on the detecting that the first link with the networkentity is lost, the first link re-established based on a secondrandom-access procedure.
 23. The method of claim 22, the establishingthe first link further comprising: exchanging random-access messageswith the network entity to establish the first link; and refraining fromexchanging radio resource control (RRC) signaling with the networkentity after establishing the first link.
 24. The method of claim 22,the first device comprising a reflective surface to forward signalsassociated with a second link from the network entity to a second devicein a wireless network.
 25. The method of claim 24, further comprising:receiving, from the network entity via the first link, a messageindicating a configuration for the reflective surface, the controllingthe state of the first device comprising controlling the reflectivesurface via the configuration.
 26. The method of claim 22, furthercomprising: failing to receive one or more periodic indicators in acontrol channel, the detecting that the first link with the networkentity is lost being based at least in part on the failing to receivethe one or more periodic indicators in the control channel.
 27. A methodfor wireless communication at a network entity, comprising: establishinga first link with a first device via a first random-access procedure,the first link comprising a control link to control a state of the firstdevice; outputting, to the first device via the first link, a messageindicating a configuration for a reflective surface; outputtingsignaling to the first device to maintain the first link with the firstdevice; and performing a second random-access procedure to re-establishthe first link with the first device after the first link with the firstdevice is lost.
 28. The method of claim 27, the establishing the firstlink comprising: exchanging random-access messages with the first devicebased at least in part on establishing the first link; and refrainingfrom exchanging radio resource control (RRC) signaling with the firstdevice after establishing the first link.
 29. The method of claim 27,the first device comprising a reflective surface for forwarding signalsassociated with a second link from the network entity to a second devicein a wireless network.
 30. The method of claim 27, the outputtingsignaling to the first device to maintain the first link with the firstdevice comprising: outputting one or more periodic indicators in acontrol channel to the first device, the first link with the firstdevice being lost when the first device fails to receive a thresholdnumber of the one or more periodic indicators.